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The influence of whole body vibration on jumping performance

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Abstract

The effects of whole body vibrations on the mechanical behaviour of human skeletal muscles were studied in 14 physically active subjects randomly assigned to the experimental (E) or control (C) group. Group E was subjected to 5 sets of vertical sinusoidal vibrations lasting up to 2 min each, for 10 min daily, for a period of 10 days. The control subjects were requested to maintain their normal activity and to avoid strength or jumping training. The subjects were tested at the beginning and at the end of the treatment. The test consisted of specific jumping on a resistive platform. Marked, significant improvements were noted in Group E in the power output and height of the best jump (by 6.1 and 12%, respectively, P<0.05) and mean jump height in continuous jumping for 5 s (by 12%, P<0.01). In contrast, no significant variations were noted in Group C. It was suggested that the effect of whole body vibration elicited a fast biological adaptation associated with neural potentiation.

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... It is this muscle flexion that improves the permeability of myocyte membranes to glucose, causing an insulin-like effect, (Behboudi et al., 2011). WBV involves nearly 100% of the body's muscles whilst traditional exercise involves only 40 -60 % of them at any one time (Behboudi et al., 2011;Bosco et al., 1998). Perchthaler, Horstman,& Grau (2013) suggest thatthe way WBV works is through activation of the central nervous system, innervating appropriate muscles in response,which attempt to minimise the soft tissue vibration occurring for protection from injury. ...
... Perchthaler, Horstman,& Grau (2013) suggest thatthe way WBV works is through activation of the central nervous system, innervating appropriate muscles in response,which attempt to minimise the soft tissue vibration occurring for protection from injury. Bosco et al. (1998) purport that WBV elicits fast biological adaptation connected to neural potentiation. Vibration also elicits an increase in total peripheral resistance. ...
... These effects were not evident 60 minutes post intervention (Torvinen et al., 2002). Bosco et al. (1998) argued that WBV treatment elicits a biological response similar to that which occurs during and after explosive power training, yet with significantly less risk of injury. Over 10 days participants were exposed to 5 x 90 secs at 26 Hz at almost 3 g, with a total exposure of 100 minutes. ...
... It is this muscle flexion that improves the permeability of myocyte membranes to glucose, causing an insulin-like effect, (Behboudi et al., 2011). WBV involves nearly 100% of the body's muscles whilst traditional exercise involves only 40 -60 % of them at any one time (Behboudi et al., 2011;Bosco et al., 1998). Perchthaler, Horstman,& Grau (2013) suggest thatthe way WBV works is through activation of the central nervous system, innervating appropriate muscles in response,which attempt to minimise the soft tissue vibration occurring for protection from injury. ...
... Perchthaler, Horstman,& Grau (2013) suggest thatthe way WBV works is through activation of the central nervous system, innervating appropriate muscles in response,which attempt to minimise the soft tissue vibration occurring for protection from injury. Bosco et al. (1998) purport that WBV elicits fast biological adaptation connected to neural potentiation. Vibration also elicits an increase in total peripheral resistance. ...
... These effects were not evident 60 minutes post intervention (Torvinen et al., 2002). Bosco et al. (1998) argued that WBV treatment elicits a biological response similar to that which occurs during and after explosive power training, yet with significantly less risk of injury. Over 10 days participants were exposed to 5 x 90 secs at 26 Hz at almost 3 g, with a total exposure of 100 minutes. ...
... [4,5] Use of whole body vibration (WBV) has shown to be an effective and easy training method to increase physical performance. [6] Currently, segmental and/or WBVs are used in different fields, ranging from not only training of elite athletes [7,8] or into the rehabilitation of individuals with anterior cruciate ligament reconstruction [9] but also as treatment for osteoporosis [10,11] and chronic low back pain [12,13] or in neurologic rehabilitation for reducing spasticity. [14] Nevertheless, the extensive use of vibrations is still contrasting. ...
... [14] Nevertheless, the extensive use of vibrations is still contrasting. In fact, even if many studies have reported remarkable improvements in muscle strength after acute and chronic vibration exposure, [4,6,[15][16][17] other authors did not find any significant effects. [18][19][20][21][22] A possible reason of this conflicting results could be due to the use of different protocols. ...
... [23] In physical training, temporary positive effects on jump height, force-velocity relationship, and muscular flexibility of the lower limbs are obtained after a few minutes (∼10 minutes) of mechanical vibration. [6,7,15,16,24] At the same time, it was observed that a prolonged exposure to vibrational treatments induces fatigue in muscle spindle with consequent reduction in reflex activity and decrease in muscular performance. [25] How a vibratory stimulus acts on neuromuscular system in muscular performance remains unclear. ...
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Article
This study was aimed to investigate the neuromuscular activity after 10 minutes of exposure to a whole body vibration (WBV) session. Twenty male young adults (24.8 ± 2.5 year olds) were randomized and divided into 2 groups: the vibration group (VG) was exposed to 10 minutes of WBV at 35 Hz; performed 10 minutes of WBV at 35 Hz (displacement = 5 mm; magnitude = 5 g); the nonvibrated group (NVG) was the placebo group that maintained the same position on the plate but without exposure to any type of vibration. Subjects were evaluated with counter movement jump (CMJ) and muscular flexibility by means of electromyographic (EMG) analysis recorded on the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and gastrocnemius lateralis (LG). The 10 minutes of WBV showed an increase in muscular flexibility, associated with a decrease of EMG activity in BF (P < .01) and jump height. The latter was associated with a reduction of EMGs activity in BF (P < .01). The control group did not show any significant difference in all considered parameters. These results support the hypothesis that 10 minutes of WBV had effects on flexibility and explosive strength performance influencing neuromuscular behavior through inhibitor effects on antagonist muscles more than the stretch reflex activity on agonist muscles.
... 14 Whole-body vibration (WBV) is considered to be a recent and promising treatment modality in exercise physiology to enhance athletic performances and therefore, a valuable addition to rehabilitation protocols, but has not been well investigated among athletes. [15][16][17] Whole-body vibration produces vertical sinusoidal oscillations, transferred to the body and perceived by the muscular-skeletal apparatus, which adapts to them rapidly through the activation of the neuromuscular reflexes. 16 The mechanism inducing muscle performance enhancements is unknown. ...
... [15][16][17] Whole-body vibration produces vertical sinusoidal oscillations, transferred to the body and perceived by the muscular-skeletal apparatus, which adapts to them rapidly through the activation of the neuromuscular reflexes. 16 The mechanism inducing muscle performance enhancements is unknown. One hypothesis is that muscle mechanical vibration induces a reflex involuntary action. ...
... The extension of the oscillatory motion determines the amplitude of the vibration (peak to peak, displacement in millimeter), the repetition rate of the cycles of oscillation denotes the frequency of the vibration (measured in Hertz), and the acceleration indicates the magnitude of the vibration (measured in g 5 9.81 m/s 2 ). 16 As studies have demonstrated, WBV can reduce the frequency and intensity of electromyographic activity, 20,[22][23][24] while increasing muscular force similarly to what is achieved with muscular strength training. 20 Recently, WBV has been adopted by high-profile sports teams as a response to the needs of athletes in intensive training, integrating or replacing muscle strength training sessions. ...
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Article
Objective: To evaluate whether an 8-week whole-body vibration training program may improve recovery of knee flexion/extension muscular strength in athletes after arthroscopic anterior cruciate ligament (ACL) reconstruction. Design: Randomized controlled trial. Setting: Single outpatient rehabilitation center. Participants: Thirty-eight female volleyball/basketball players (aged between 20 and 30), randomized into 2 treatment groups. Interventions: During a standardized six-month rehabilitation program, from week 13 to week 20 after surgery, the whole-body vibration group (n = 19) and the control group (n = 19) performed additional static knee flexor/extensor exercises on a vibration platform. For the whole-body vibration group, the vibration platform was set to 2.5 mm of amplitude and 26 Hz of frequency. The control group followed the same whole-body vibration board training with no vibrations. Main outcome measures: All patients were evaluated using an isokinetic strength test with a Biodex dynamometer at the beginning and at the end of the additional treatment protocol. The parameters tested were the peak torque and the maximum power of knee flexor and extensor muscles performing strength and endurance tests. Results: No vibration-related side effects were observed. Improvements were noticed in both groups, but increase in knee muscle isokinetic strength values was statistically significant in the whole-body vibration group when compared with the control group (differences in extension: peak torque 11.316/10.263 N·m and maximum power 13.684/11.211 W; flexion: peak torque 9.632/11.105 N·m and maximum power 10.158/9.474 W; P < 0.001). Conclusions: When combined with a standardized rehabilitation program, whole-body vibration may increase muscular strength and be an effective additional treatment option in the rehabilitation of athletes after ACL arthroscopic reconstruction.
... Low-amplitude, low-frequency mechanical stimulation of the human body is a safe and active method to improve muscle strength, bone remodeling, and cartilage preservation [2]. The effects of whole-body vibration (WBV) have been considered with subjects exercising on vibrating plates [3,4] that produce sinusoidal vibrations. Low frequency vibration has also been applied locally by means of vibrating cables and vibrating dumbbells [5]. ...
... Exhaustive protracted strength training is known to stimulate a specific neuromuscular and hormonal adaptive reaction in the human body in little time [5]. Even less knowledge is accessible in respect to fatigue, relative strength loss, and hormonal changes during one severe session of exercises [4]. It should be remembered that detailed packages for strength and explosive power training are based on exercises performed with fast and intense variation of gravitational acceleration [5]. ...
... In this connection, Prof. Bosco and coauthors discovered that mechanical vibrations applied to the whole body could create modifications in gravitational conditions. Whole-body vibration applied for ten minutes during a ten-day treatment stimulated an improvement in explosive power performances in physically active subjects and it was observed how human skeletal muscle reacted to a single session of ten minutes application of whole-body vibration in athletes [4]. The use of vibrations with exercise is quite a recent innovation. ...
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Article
Musculoskeletal vibration stimulation is the topic chosen for this review. The aim is to discuss this interesting, but poorly analyzed topic in the current literature in order to explain and help readers to better understand the effects of vibration used as an exercise intervention and therapy for muscle, bone, and cartilage tissues. The use of vibration stimulation for enhancing athletic performance and therapeutic use is considered an important matter of medical biology that has developed in the last three decades. Current evidence suggests that vibration is effective in enhancing musculoskeletal strength and power capacity and improving physical conditions in patients with related disorders such as osteoporosis and osteoarthritis, although the mechanisms mediating these effects are still not well known.
... In this range there are no dangerous effects. Daily WBV has been applied for 10 min during a daily session and for 10-day treatment period [1]. The sessions are preceded by 5-min warming up on cycle ergometer (25 km/h) and 5-min static stretching for quadriceps and triceps surae muscles are necessary before the WBV [1]. ...
... Daily WBV has been applied for 10 min during a daily session and for 10-day treatment period [1]. The sessions are preceded by 5-min warming up on cycle ergometer (25 km/h) and 5-min static stretching for quadriceps and triceps surae muscles are necessary before the WBV [1]. ...
... The training effect occurred to be various when 26 Hz, 10-min daily session were applied during 10 days. The average jumping height increased by 11.9% in 5-sec continuous jumping but no changes appeared in power output in this test, and in counter movement jump [1]. Five training sessions (30 Hz, 8 mm) did not affect maximal voluntary contraction and voluntary activation of leg extensors [11]. ...
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Article
Whole body vibration (WBV) has been suggested as a possible training form to additionally stimulate adaptation processes in skeletal muscles. Changes in gravitational conditions can be produced by mechanical vibration applied to the whole body. Attempts have been made to use WBV to potentate the training effects with improved strength and power. WBV has also been recommended in order to avoid sarcopenia and osteoporosis in elderly people. There are suggestions to use WBV as means to speed up the recovery processes after training sessions in athletes. The aim of the present brief review is to highlight the WBV effects which may promote exercise training and may be useful for improved strength and power. The effect of vibration on nervous regulation Vibration is a mechanical stimulus characterized by oscillatory motion [5]. Its influence is related to the frequency and amplitude of oscillatory movements. The amplitude is measured by peak to peak displacement in mm during the vibration. The repetition rate of the cycles determines the frequency of the vibration and is measured in Hz. Depending on the specific amplitude and frequencies, vibration can be dangerous. The low frequency and low amplitude of mechanical stimulation in human body is a safe and effective way to exercise neuromuscular structures [2, 3, 5, 7, 10, 19]. The WBV exercise devices which are available at present, deliver vibrations in the range of frequencies between 15 and 60 Hz and displacements 1 mm to 10 mm. In this range there are no dangerous effects. Daily WBV has been applied for 10 min during a daily session and for 10-day treatment period [1]. The sessions are preceded by 5-min warming up on cycle ergometer (25 km/h) and 5-min static stretching for quadriceps and triceps surae muscles are necessary before the WBV [1].
... The recent positive findings in low-frequency vibration research specific to muscle adaptation has led to studies focused on using vibration as an exercise method; this is referred to as whole-body vibration (WBV) that involves a vibrating platform. The idea of WBV is to utilize the isolated positive effects, such as muscle spindle activation 1,3,15,16 and muscular performance 8,[17][18][19] , and apply them to exercise and training for the entire body. ...
... In contrast to previous findings 12,17,30,31,45 current findings reported no significant increase in CMJ following acute WBV. The disparity between results appears to be the variability of WBV parameters (vibration frequency, amplitude and duration) and the use of different vibration platforms. ...
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Article
Objectives: To determine if a change in vertical jump performance from acute whole-body vibration can be explained by indirectly assessing spindle sensitivity from electromechanical delay. Methods: Using a counter-balanced design, twenty college-aged participants performed whole-body vibration (WBV) and control treatments. WBV included 10 intervals (26 Hz, 3.6 mm) of 60 s in a half-squat followed by 60 s of rest. After 5 intervals, participants rested for 6-minutes before commencing the final 5 intervals. For the control, the exact same protocol of whole-body vibration was performed but without vibration. Electromechanical delay and vertical jump were assessed at baseline, during the 6-minute rest period and immediately after whole-body vibration and control. Results: There were no differences between treatments, for both electromechanical delay (F(2, 38)=1.385, p=0.263) and vertical jump (F(2, 38)=0.040, p<0.96). Whole-body vibration had no effect on vertical jump performance. Conclusion: The current whole-body vibration protocol is not effective for acute vertical jump or electromechanical delay enhancement. Also, since there was no effect on electromechanical delay, this suggests that whole-body vibration did not enhance muscle spindle sensitivity for the parameters examined.
... Team sport athletes have also benefited from the short-term use of vibration to improve muscular power. The pioneering work from the late Carmelo Bosco [32] revealed that when handball and waterpolo athletes were exposed to 10 days of intermittent vibration (26 Hz, 10 mm), 12% improvement in CMJ was observed compared to no change in control (no vibration) [32]. A longer duration study of 15 weeks in young female basketballers revealed that the addition of vibration to their normal training increased CMJ by 10%, [33]. ...
... Team sport athletes have also benefited from the short-term use of vibration to improve muscular power. The pioneering work from the late Carmelo Bosco [32] revealed that when handball and waterpolo athletes were exposed to 10 days of intermittent vibration (26 Hz, 10 mm), 12% improvement in CMJ was observed compared to no change in control (no vibration) [32]. A longer duration study of 15 weeks in young female basketballers revealed that the addition of vibration to their normal training increased CMJ by 10%, [33]. ...
Chapter
There are numerous training methods and equipment that can assist an athlete’s performance. Vibration exercise has gained popularity amongst coaches and conditioning experts for athletic development. The use of vibration exercise is varied and includes a single session or repeated bouts of exposure over weeks. Vibration has been included for injury rehabilitation, strength, explosive power, sprinting and balance and for accelerating recovery. Evidence suggests that vibration can have positive influence on explosive power and flexibility, but effects on strength measures and sprinting are less convincing for single session and short-term exposure. Additionally, vibration as a recovery strategy has little influence. Vibration exercise can be used in conjunction with other training methods, but other traditional training may produce the same or greater results. Often vibration is performed in the general preparation phase of training (off-season) in the anticipation that it will transfer to actual performance. However, the athlete’s requirements need to be considered, along with their timing and periodization.
... WBV is a frequently used exercise modality employed in fitness and health centers for the purpose of increasing muscle strength and balance (Machado et al., 2010;Sitjà-Rabert et al., 2012;Delecluse et al., 2003;Petit et al., 2010;Bosco et al., 1998;Mahieu et al., 2006;Giorgos et al., 2007;Savelberg et al., 2007;Luo et al., 2005;Adams et al., 2009), and flexibility (Fagnani et al., 2006;Dallas et al., 2012;Behm et al., 2011;Siegmund et al., 2014;Samson et al., 2012;Dadebo et al., 2004;Torvinen et al., 2002). ...
... Short-term WBV training was shown to increase jump height scores (Bosco et al., 1998). In addition, acute WBV training was reported to increase jump height scores (Bosco et al., 2000). ...
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Article
Whole Body Vibration (WBV) is a type of exercise commonly applied as a modern exercise technique. The purpose of the present study was to examine the effects of WBV applied for 10-week on strength, flexibility and agility in taekwondo athletes. A total of 23 healthy young males participated in the present study. The athletes were separated randomly into two groups as the control group (n=11) and whole body vibration training group (n=12). The WBV training group did training 3 days a week for 10 weeks. The Control Group did not do any trainings. The hand grip strength test, vertical jump test, sit-reach test, agility t-test were applied to the WBV training group and control group before and after the 10-week WBV training. The comparisons between the groups were analyzed by using an independent sample t-test at a significance level of p<0.05. No statistically significant differences were detected between the pre-test hand grip strength, vertical jump test, sit-reach test and agility t-test results of the WBV training group and control group according to the Independent sample t test. In the post-test results, statistically significant differences were detected between the vertical jump test, sit-reach test, agility t-test however, no statistically significant differences were detected between the hand grip strength results. The intra-group comparisons were made according to the paired sample t test at a significance level of p<0.05. Although statistically significant differences were detected in the WBV training group between the pre-test-post-test, vertical jump test, sit-reach test, agility t-test values, no statistically significant differences were detected between the hand grip strength results. No statistically significant differences were detected between the hand grip strength, vertical jump, sit-reach, agility t-test pre-test and post-test results of the control group. Long-term whole body vibration training has positive strength, flexibility and agility values.
... In literature, there are a lot of investigations about the beneficial effects of vibration on muscular performance through a neural adaptation (Bosco et al., 1998;Delecluse et al., 2003;Verschueren et al., 2004a;Roelants et al., 2004;Torvinen et al., 2002;Torvinen et al., 2003;Verschueren et al., 2004b). However, there is no consensus about the mechanism of the vibratory stimulus, and it is possible that the mechanism may be explained by vibration stimulation affecting motor neuron excitability, and/or fast twitch fibre recruitment (Rittweger et al., 2000). ...
... However, there is no consensus about the mechanism of the vibratory stimulus, and it is possible that the mechanism may be explained by vibration stimulation affecting motor neuron excitability, and/or fast twitch fibre recruitment (Rittweger et al., 2000). It is known that this adaptation is similar to resistance training (Bosco et al., 1998;Delecluse et al., 2003;Aagaard et al., 2002;Bosco et al., 2000). When ...
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Article
A limited number of acute whole body vibration (WBV) studies have investigated the effects of WBV treatments which were applied with different vibration frequencies and amplitude combinations on lower extremity muscle activation of well-trained athletes from different sports branches. To compare the effects of WBV on lower extremity muscle activation via Surface Electromyography (sEMG) of well-trained athletes from different sports branches (soccer, basketball and swimming) during static and dynamic squat exercises. sEMG activities of Tibialis Anterior (TA), Gastrocnemius Medialis (GM), Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) muscles of 7 male soccer players, 7 male basketball players, and 6 male swimmers were recorded during WBV applied in static squat and dynamic squat positions with different frequencies (30-35-40 Hz) and amplitude (2-4 mm) combinations separated from each other by 5 min passive rest periods. Each combination was applied for 30 sec. The highest muscle activation was determined in TA of the swimmers compared to soccer players during static squat with 4mm-30Hz WBV application (p=0.027). The lowest muscle activation was also determined in VL of the swimmers compared to soccer players during static squat with 2mm-40Hz WBV (p=0.049). During dynamic squat with 4mm-40Hz WBV, the highest muscle activity was determined in RF of the basketball players compared to swimmers (p=0.030). However, dynamic squat with 2mm-40Hz WBV application gave rise to the lowest muscle activation in VL of the basketball players compared to soccer players (p=0.042). Well-trained athletes from different sports branches demonstrated different neuromuscular responses to acute WBV treatments. WBV during dynamic squatting which was applied with 4mm-40 Hz may be more beneficial in enhancing neuromuscular performance acutely for well-trained male athletes since it resulted in higher levels of muscular activation responses according to the present study.
... L'applicazione di vibrazioni meccaniche al corpo umano come esercizio fisico sta diventando una metodica piuttosto diffusa per lo sviluppo di forza muscolare, flessibilità e potenza (3,5,21). Le prime applicazioni di vibrazioni furono condotte da Granville nel 1881 (21) nel trattamento del dolore e successivamente impiegate nella terapia fisica per aumentare l'eccitabilità dei motoneuroni alfa e gamma, permettendo così al paziente di raggiungere un maggior controllo volontario (23). ...
... Effetti delle whole-body vibration. Gli effetti delle vibrazioni sulla forza muscolare e sulla potenza sono stati ampiamente esaminati usando diversi protocolli di trattamento: in acuto, residuo (4,5,9,31,35,38) ed in seguito ad esposizione cronica (3,10,11,13,32,33,36,37). Al contrario, l'applicazione di WBV come metodo per aumentare la flessibilità è stata investigata in pochi esperimenti (7,16,22,39). ...
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Article
La flessibilità: definizione, misurazione e nuove metodiche di incremento. In letteratura, opinioni divergenti sull'importanza della flessibilità in seguito a traumi e nella performance rappresentano la norma. In parte, il dibattito è il risultato dalla mancanza di definizioni-misurazioni consensuali e la mancanza di comprensione scientifica sui fattori determinanti la flessibilità. Recentemente, le vibrazioni totali del corpo sono state utilizzate come metodo per incrementare la flessibilità muscolare in acuto ed in cronico. Parole chiave: flessibilità muscolare, stretching, PNF, vibrazioni totali del corpo individualizzate. Summary Divergent views on the importance of flexibility in injury and athletic performance are the rule. In part, debates about flexibility result from lack of consensual definitions and measurements and lack of scientific understanding about determinants of flexibility. While researchers have extensively studied endurance and strength training, they have placed less emphasis on flexibility training. Recently, enhancement on hamstring flexibility through the application of individualized whole-body vibration has also been reported after both acute and chronic treatment.
... It has been indicated that enhanced neuromuscular response i.e. increase in muscle force and power after indirect vibrations may be similar to the effect of resistance/strength training [2], [22], [25], [94], [95]. An explanation for this link put forward by [2] is briefly discussed below in the next paragraph. ...
... Resistance and strength training exercises use additional gravitational load to increase strength and power. Similarly, in vibration exercise gravitational load can be altered through the adjustments in the vibration frequency and amplitude which changes the acceleration level and hence the load delivered to the body [22]- [25], [94]. ...
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Thesis
Vibration stimulation has been used as a tool to relieve muscle pain and spasm in physical therapy for many years. However recently, vibration, mainly Whole Body Vibration (WBV), has been increasingly studied and used as an exercise intervention in sports and rehabilitation. Although the physiological mechanisms which guide the body’s response to this exercise modality are relatively poorly understood, evidence indicates that vibration can enhance muscle strength, power, and flexibility as well as increase bone mineral density in the general population. Evidence also suggests that the neuromuscular response to vibration stimulation depends on muscle length, stretch level (contraction) along with the vibration characteristics. One way to alter muscle length and contraction levels while receiving vibration is to superimpose the stimulation on graded isometric contraction. However, current WBV device designs cannot facilitate the delivery of vibration stimulation superimposed on graded isometric voluntary contraction. The aim of this PhD project was twofold, firstly to develop and evaluate a prototype WBV device which enables the delivery of vibration stimulation that can be superimposed on graded isometric contraction and secondly, to assess the neuromuscular responses to vibration superimposed on graded isometric contractions in lower limbs using this device. Due to the novelty of the device design and the method of the delivery, this study initially investigated the effects of different vibration frequencies and amplitudes combined with various effort levels on neuromuscular responses in lower limbs. The results of this study confirm that isometric contraction superimposed on vibration stimulation induce enhanced neuromuscular activity in the lower limbs. The results also confirm that although the neuromuscular responses to vibration depend on multiple factors the main determinants seem to be the vibration frequency, amplitude and muscle contraction /force level. Another limitation of most existing vibration devices is that they are not capable of delivering frequency of the vibration independent of amplitude and vice versa. Further, the evidence suggests that vibration amplitude can play an important role in neuromuscular response to vibration, especially when superimposed with graded contraction/force levels. To address the above limitation, the second aim of this PhD project was to develop and evaluate a prototype miniature upper limb vibration device capable of delivering precise and independent vibration frequency and amplitude stimulation. The miniature upper limb vibration (ULV) device with piezo actuators developed for this thesis, enables precise vibration stimulation to be delivered in a seated position with graded voluntary contraction superimposed. The neuromuscular responses to vibration superimposed on graded isometric contractions in upper limbs were also assessed by investigating the fatiguing effects of superimposed vibration stimulation using this newly developed device. This study is the first to investigate and compare the fatiguing effects of superimposed vibration stimulation pre and postvibration exercise in upper limbs. The results of this study confirm that isometric contraction superimposed on vibration stimulation lead to increased fatigue levels and neuromuscular activity in upper limbs. The results also indicate that post-vibration treatment the muscles display enhanced force generation capability associated with lower fatigue levels. In summary, two (WBV and ULV) novel vibration exercise devices were successfully developed and evaluated for this thesis. The results of the studies on these devices confirm that vibration stimulation superimposed on graded isometric contraction can induce higher neuromuscular activity compared to isometric contraction alone in both upper and lower limbs. However the effects of vibration frequency, amplitude and contraction/force levels seem to differ between the upper and lower limbs.
... occurrence, increasing muscle spindle activity and consequent stretch reflex (Cardinale & Bosco, 2003). Bosco et al. (1998) and Bosco et al. (1999) pointed that the increase in muscle performance is due to neural factors, which are similar to those seen after weeks of conventional resistance and power training. The load on the neuromuscular system is imposed by vibration frequency and amplitude. ...
... AVibration exercise ccording to Luo et al. (2005), in order to activate the muscle effectively, vibration frequencies should be between 30Hz and 50Hz. Bosco et al. (1998) has reported an increase in vertical jump performance with a frequency of 26 Hz but no rationale was given for the selection of the vibration frequency. Vibration exercise is mostly practiced as wholebody vibration while standing on oscillating platforms. ...
Article
Introduction: Vibration exercise has been increasing in popularity although the impact of this exercise modality is still under investigation. Vibration exercise is practiced mostly while standing on vibration platforms, as whole body vibration. Several researchers have studied the effects of exposure to whole body vibration in strength, flexibility, equilibrium and blood flow, but the use of medical thermography in these investigations is still very limited. The aim of this research is to study the impact of acute exposure to whole body vibration in the skin temperature and thermal symmetry of the lower extremities in healthy subjects. Methods: The skin temperature of 24 healthy and untrained subjects, randomly assigned to two groups (vibration and no vibration), was accessed using medical thermography before and after exposure to the intervention protocol. All subjects followed a protocol suggested in previous literature for image capturing. Thermograms were obtained from several lower limb regions of interest in different views before and after exposure to vibration. The mechanical stimulation was provided by the Power PlateR with parameters set at a frequency of 35 Hz, high amplitude (5-6 mm) for 5 minutes. Results: The analyzed regions of interest mean temperature decreased significantly in the control group in the posterior thighs, anterior knees, lower legs and ankles (p ≤ 0.05). Acute exposure to whole-body vibration was responsible for a significant decrease in temperature of the anterior thighs, lateral aspect of knees and medial aspect of the left knee (p ≤ 0.05) and an increase in temperature of the lower legs and ankles (p > 0.05). The highest temperature symmetry difference was observed in the lateral aspect of the ankle (0.29±0.23 °C) followed by the medial aspect of the ankle (0.27±0.22 °C) and the medial aspect of the knee (0.26±0.14 °C) and whole-body vibration increased temperature symmetry difference in all regions of interest. Discussion: The results show that the exposure to 5 minutes of vibration (35 Hz) in a single session has an effect in the skin temperatures of the lower extremities. In the control group, at the regions of interest with significant statistical difference, a mean decrease in temperature of 0.48 °C was found and in the experimental group the mean temperature decrease was of 0.41 °C. In the experimental group, at the regions of interest with mean temperature increases, the mean difference observed was of 0.24 °C. Caution should be taken before vibration exercise prescription since the effects in microcirculation are not fully understood. The results of this investigation are expected to contribute to better understand specific pathologies affecting the lower limbs.
... Many studies were conducted to investigate the influence of whole-body vibration (WBV) training on sports performance. Their findings showed the positive influence of WBV training on neuromuscular activation, muscle strength, power, movement speed, jump, flexibility and balance [7][8][9][10][11][12][13][14]. The comprehensive description of WBV currently used by athletes includes type of equipment, physics principles, frequency, amplitude, acceleration, muscle and tendon mechanics, and neuronal and physiological responses [6]. ...
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Article
Objective: The review aimed to investigate the effects of whole-body vibration (WBV) on neuromuscular activation and explosive power. Methods: Keywords related to whole-body vibration, neuromuscular activation and explosive power were used to search four databases (PubMed, Web of Science, Google Scholar and EBSCO-MEDLINE) for relevant studies published between January 2000 and August 2021. The methodology of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used. The eligibility criteria for the meta-analysis were based on PICOST principles. Methodological assessment used the Cochrane scale. Heterogeneity and publication bias were assessed by I2 index and funnel plots, respectively. The WBV training cycle is a random effect model. Publication bias was also assessed based on funnel plots. This study was registered in PROSPERO (CRD42021279439). Results: A total of 156 participants data in 18 studies met the criteria and were included in the meta-analysis for quantitative synthesis. Results of the meta-analysis showed significant improvements in lower limb neuromuscular activation immediately after WBV compared with the baseline (SMD=0.51; 95% CI: 0.26, 0.76; p<0.001), and no significant heterogeneity was observed (I2=38%, p=0.07). In addition, the highest increase in lower limb explosive power was observed (SMD=0.32; 95% CI: 0.11, 0.52; p=0.002), and no significant heterogeneity (I2=0%, p=0.80) was noted. Conclusions: WBV training could improve neuromuscular activation and explosive power of the lower limb. However, due to different vibration conditions, further research should be conducted to determine standardized protocols targeting performance improvement in athletes and healthy personnel experienced in training.
... 1 No entanto, o uso extensivo de vibrações ainda é contrastante. De fato, mesmo que muitos estudos tenham relatado melhorias notáveis na força muscular após a exposição aguda e crônica à vibração [11][12][13][14] , outros autores não encontraram quaisquer efeitos. 15,16 Uma possível razão para estes resultados de conflito pode ser devido à utilização de diferentes protocolos. ...
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O treinamento com vibração de corpo inteiro (WBV, do inglês Whole Body Vibration) foi recentemente proposto como um método de treinamento com potencial para melhorar a composição corporal e prevenir osteoporose e perda de massa óssea18. Nos últimos anos, alguns estudos mostraram que o WBV pode ser um modo de treinamento benéfico em pacientes com esclerose múltipla19, diabetes tipo 220, doença pulmonar obstrutiva crônica21 e receptores de transplante cardíaco22. OBJETIVO: Verificar o efeito da vibração de corpo inteiro no paciente hospitalizado.MÉTODOS: Revisão de ensaios clínicos controlados randomizados (ECR) e estudo piloto nas bases de dados PubMed, Cochrane Library, Medline e PEDro. Ultilizou-se Escala PEDro para análise da qualidade metodológica. RESULTADOS: Foram incluídos 6 artigos, publicados entre os anos 2014 e 2018, A terapia mostrou-se segura e viável em pacientes hospitalizados, havendo significância em alguns desfechos TC6 e VEF1, entretanto não houve diferença estatística na PA, FC, CAT e SGRQ. CONCLUSÃO: A terapia mostrou significância nos desfechos TC6 e VEF1.
... Vol. 62 -no. 6 The Journal of SporTS Medicine and phySical fiTneSS 793 ...
Article
Background: We tested the hypothesis that Whole Body Vibration (WBV) positively affects the fatigue process ensuing from repeated bouts of maximal efforts, as induced by repeated sprints ability (RSA). Eleven male soccer players performed three sets of six repeated shuttle sprints (40 metres). Methods: Eleven male soccer players (age 23,6±4,5 years) were cross-randomized to perform WBW before RSA and during the recovery between sets (WBV-with) or to warm-up and passive recovery between sets (WBV-without). The effects of WBV were quantified by sprint time (ST) and blood lactate concentration (LA), collected up to 15th min after completion of tests. Results: ST during RSA showed a better maintenance of performance in the WBV-with compared to WBV-without condition in all three sets, reaching a statistical significance between-groups during the 2nd and 3rd set (P< 0.05). No significant differences in ST over the sets were detected in WBVwith, whereas a significant decrease was observed in the WBV-without condition (P<0.001). LA recovered significantly faster from the 9th to 15th minute of recovery in WBV-with as compared to WBV-without (P<0.05). Conclusions: These findings would indicate that WBV performed during recovery between RSA sets is capable of delaying the onset of muscle fatigue resulting in a better maintenance of sprint performance.
... The post-values of the study group were altogether higher than the post-values of the control group in respect to vertical jump height that is compatible with the outcome of Bosco et al. [51] who detailed that there was a noteworthy improvement in the jumping performance for children having daily vertical sinusoidal vibrations at a frequency of 26 Hz following 10-day of the training program. Moreover, WBV training improved equilibrium, deftness agility, and power [52], and the concentric torque of quadriceps muscles [53], and this in turn underpins the remarkable improvement in lower-extremity muscle strength and VJH of the study group. ...
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Article
Background Hemiplegic cerebral palsy (CP) enormously affects the quadriceps and hamstring muscles. It causes weakness in the affected lower-extremity muscles in addition to muscle imbalance and inadequate power production, especially in the ankle plantar-flexor and knee extensor muscles. It also causes anomalous delayed myoelectrical action of the medial hamstring. A whole-body vibration (WBV) exercise can diminish muscle spasticity and improve walking speed, muscle strength, and gross motor function without causing unfavorable impacts in adults suffering from CP. Thus, the aim of this study is to investigate the impacts of WBV training associated with conventional physical therapy on the quadriceps and hamstring muscle strength, endurance, and power in children with hemiparetic CP. Results The post-intervention values of the quadriceps and hamstring muscle force, endurance, and power were significantly higher than the pre-intervention values for both groups ( p = 0.001). The post-intervention values of the study group were significantly higher than the control group (quadriceps force, p = 0.015; hamstring force, p = 0.030; endurance, p = 0.025; power, p = 0.014). Conclusion The 8 weeks of WBV training that was added to traditional physical therapy was more successful in improving the quadriceps and hamstring muscle strength, endurance, and power in children with hemiparetic CP when compared to traditional physical therapy alone.
... La vibración de cuerpo entero (WBV) es un entrenamiento neuromuscular que utiliza la respuesta fisiológica a los estímulos vibratorios y ha sido probado en varios campos (Bosco et al., 1998(Bosco et al., , 1999(Bosco et al., , 2000. En cuanto a los efectos a corto plazo del WBV sobre el rendimiento muscular, estudios previos demuestran aumentos significativos en la fuerza isométrica de piernas, potencia y altura del salto con una sola sesión (Torvinen et al., 2003;Cardinale & Lim, 2003). ...
Book
El International Congress LifeAge: Exercise Prescription for Healthy Active Ageing ha sido el acto final del Proyecto Europeo Promoting the shift sedentary Lifestyle towards active Ageing-LifeAge, financiado por el programa Erasmus+, en el que la Universidad Católica san Antonio de Murcia ha ejercido la función de coordinadora del proyecto. Este proyecto se ha desarrollado desde el año 2018 al 2020 y han formado parte de este diferentes universidades españolas e internacionales. Las universidades que han participado han sido la Unviersidad de Cádiz (España), Università degli Studi di Roma “Foro Itálico” (Rome), Lapland University of Applied Sciences (Finland), University of Limerick (Ireland) y Latvijas Universitāte-University of Latvia (Latvia). Dada la recopilación de datos de Eurostat sobre el cambio demográfico esperado en Europa, la mayoría de los países europeos se enfrentarán a un cambio demográfico drástico en los próximos 45 años. En particular, se espera que la proporción de personas de 64 años o más aumente drásticamente. Teniendo en cuenta estos números, se podría esperar que el envejecimiento de las sociedades sea un tema importante en la investigación sociológica. Sin embargo, si bien el envejecimiento en general y los ancianos en particular han sido temas de investigación en salud durante mucho tiempo, son objetos relativamente jóvenes de investigación sociológica. Este proyecto tuvo como objetivo contribuir a aumentar la conciencia social de la necesidad de la actividad física como base de un estilo de vida saludable mediante el cambio de hábitos de adultos y ancianos. El motivo de emprender este proyecto fue abordar los desafíos de la obesidad creciente y evaluar las consecuencias para la salud del envejecimiento y el sedentarismo entre los adultos y ancianos de los países en desarrollo que participan en el proyecto y concienciar sobre la importancia del estilo de vida activo y la nutrición saludable en todos los países involucrados como socios. Combinar la actividad física y la dieta equilibrada es la forma más eficaz de aumentar la salud general, el desarrollo mental en adultos y ancianos y de reducir el riesgo de enfermedades crónicas, sarcopenia/dinapenia y baja fuerza y capacidad funcional. De esta forma, el presente proyecto se ha desarrollado para dar respuesta a las necesidades actuales: – N1: necesidad de cambiar el comportamiento sedentario de los adultos y las personas mayores en la UE. – N2: necesidad de cambiar los hábitos nutricionales de los adultos y las personas mayores en la UE. – N3: necesidad de promover un estilo de vida saludable entre los adultos y las personas mayores en la UE. – N4: necesidad de implementar prescripción de ejercicio para prevenir y mejorar enfermedades crónicas, capacidad funcional, sarcopenia, fuerza en el contexto de la actividad física de adultos y personas mayores en la UE. – N5: necesidad de superar las barreras a la actividad física de adultos y personas mayores en la UE. – N6: necesidad de cambiar la motivación para incrementar la adherencia a un estilo de vida saludable de adultos y ancianos en UE. Los días 10 y 11 de diciembre, como acto final del proyecto, científicos, profesionales, investigadores, profesores y estudiantes se dieron cita en el International Congress LifeAge: Exercise Prescription for Healthy Active Ageing, donde se alternaron conferencias y ponencias, mesas redondas, comunicaciones y pósteres de la mano de los más relevantes profesionales en la materia. El congreso fue ofreció un momento de encuentro, comunicación y discusión para avanzar en la comprensión de la relación de la actividad física, estilo de vida saludable y envejecimiento. Se presenta a continuación la información presentada en dicho congreso.
... Los tests de salto vertical serán realizados registrándose el tiempo de vuelo (tf). La altura alcanzada por el centro de gravedad se calculará por medio de la fórmula (Bosco et al., 1998) H= tf2*g*1/8 (m) (donde, H = altura alcanzada; tf = tiempo de vuelo; g = aceleración de la gravedad). El ángulo de rodilla fue libre con fijación de las extremidades superiores en la cintura. ...
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Article
El fútbol es un deporte colectivo donde, para alcanzar el éxito, los jugadores necesitan de habilidades técnicas, tácticas y físicas, fundamentalmente de carácter intermitente siendo éstas acciones las que determinan el rendimiento. Un ejemplo de acciones de este tipo son los saltos. Este gesto deportivo esta correlacionado con la fuerza máxima, entendiendo que una mayor producción de fuerza permite una mayor generación de altura en dicho gesto. El objetivo de este trabajo es estudiar el efecto de entrenamiento de fuerza en sistema isoinercial sobre la mejora del Salto con Contramovimiento y analizar los cambios en la altura del mismo después de un programa de entrenamiento de 15 semanas, realizado sobre jóvenes futbolistas de élite. Los resultados obtenidos, muestran que no existen cambios significativos en esta variable de análisis (p< 0,05) por lo que se concluye que este tipo de entrenamiento con la duración especificada no tiene efectos sobre el rendimiento en la altura del salto (CMJ).Palabras clave: Entrenamiento Isoinercial, Futbolistas, Rendimiento, CMJ.Abstract: Soccer is a team sport where, to achieve success, players need of technical, tactical and physical skills, mainly intermittent character being such actions which determine the performance. An example of such actions is the jumpers. This sports actions is correlated with the maximal strength, understanding that force production allows greater height in this actions. The aim is to study the effects of strength training using a isoinertial device on Countermovement Jump ability and to analyze the changes in height after 15 weeks program training in young elite soccer players. There are no significant changes after to analyze the results (p< 0,05), so it is concluded that this type of training with certified duration has no effect on performance in height jump (CMJ).Keywords: Isoinertial Training, Soccers Players, Performance, CMJ.
... The initial studies in the fields of occupational therapy and work physiology considered mechanical vibration as an environmental stressor: many blue-collar workers exposed to chronic mechanical vibration reported vertigo, motion sickness, and low back pain (Helmkamp et al. 1984). Concurrently and somewhat paradoxically, sport scientists as early as 1978 also started to explore the application of mechanical vibration as a potential stimulus for increasing muscle function and athletic performance (Bosco et al. 1998(Bosco et al. , 1999bIssurin et al. 1994;Mester et al. 1999;Nazarov and Spivak 1985;Zagorskaia 1978). The reader is referred to a previous review that provides a comprehensive description of whole body vibration currently used by athletes, including device types, physics principles, frequency, amplitude, acceleration, muscle and tendon mechanics, and neuronal and physiological responses (Rittweger 2010). ...
Article
Purpose We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Methods Systematic literature review and meta-analysis. Results Whole body vibration combined with exercise had an overall 0.3 % acute effect on maximal voluntary leg force (−6.4 %, effect size = −0.43, 1 study), leg power (4.7 %, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 %, effect size = −0.12 to 0.22, 2 studies), and athletic performance (−1.9 %, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 % chronic effect on maximal voluntary leg force (14.6 %, weighted mean effect size = 0.44, 5 studies), leg power (10.7 %, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 %, effect size = 0.57 to 0.61, 2 studies), and athletic performance (−1.2 %, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Conclusions Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.
... A multitude of studies have been conducted using a variety of methods, vibration protocols, and measurements (30), such as that of assessment on vibration's response on muscular strength and power (15,19,27,33,36). To test the potential effects of vibration in athletic performance, some studies have examined the effects of vibration on jumping, sprinting, agility, and change of direction performances (4,10,11,32). Furthermore, WBV was also assessed for balance and flexibility (12,19). ...
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This study aimed to examine the effects of adding whole-body vibration (WBV) within a realistic dynamic warm-up to potentiate reactive strength performance. Twelve highly-trained sprinters (8 males and 4 females, age: 22.6±2.6yr; stature: 1.68±0.08m; body mass: 62.4±11.2kg; competitive experience: 6.7±2.4yr) completed 2 experimental conditions: dynamic warm-up + WBV or dynamic warm-up alone (control: CON) in a balanced random, crossover manner. WBV was performed on a Power Plate Pro7 device (frequency: 40Hz, amplitude: 6mm) along with two exercises, 10 repetitions of squat and 10 repetitions of calf raise exercises during the first and second 30-s period, respectively of the total 60-s WBV exposure. For the CON, the same protocol was applied with the vibratory platform turned off. Reactive Strength Index (RSI) was obtained from a 35-cm height of drop jump at pre and 1-min post warm-up. The best (RSIbest) and mean (RSImean) values were analysed subsequently. The main effect of Time indicated an identical increase in WBV and CON for RSIbest (effect size (ES): 0.60; 14.5% difference; p=0.0005 and ES: 0.64; 16.0%; p=0.0005, respectively) and for RSImean (ES: 0.64; 16.0%; p=0.0005 and ES: 0.64; 16.0%; p=0.0005). There was no main effect (p>0.05) of Condition (between-group), and Condition*Time interaction. No statistical differences (p>0.05) were detected in magnitude of changes for WBV vs. CON in each sub-group, however, lower-level sprinters (n=6) responded better during WBV (6.1% and 5.7% increases in RSImean and RSIbest, respectively), while higher-level group did poorer (-4.6% and -5.5%). The data suggest that the effects of WBV exposure may depend on athlete’s ability levels, maybe more beneficial to sub-elite but unnecessary for elite athletes. Collectively, a proper dynamic warm-up was sufficient to elicit positive effect on reactive strength performance. Journal of Australian Strength & Conditioning. 27(07):14-22, 2019
... The reliability for the DJ height was estimated to be 0.93 (p< .001). The height of rise of the centre of mass in all jump tests was determined by the flight time according to the method of Asmussen and Bonde-Petersen (1974) and used in order to analyze the explosive strength characteristics of the leg muscles as reported elsewhere (Bosco et al., 1998). Jump height, was calculated using h = g tf2/8, Where tf is the flight time and g is the acceleration due to gravity (9.81 m . ...
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Article
The purpose of this study was to examine the post activation potentiation (PAP) effect of two different conditioning stimuli (CS) on drop jump (DJ) parameters on young female gymnasts. Thirty young female artistic gymnasts, aged 8 to 13 years old performed two protocols of either double tuck jumps (DTJ: 2 sets of 5 repetitions) or legs blocking action (LBA: 2 sets of 5 repetitions) in a within-subject randomized design. Before and immediately after the PAP treatment and 4, 8, 12, and 16 min after, jumping ability was measured by performing a drop jump (DJ). Statistical analysis revealed significant interaction effect between the two CS for DJ height (p < 0.002), time flight (p < 0.002) and take-off velocity (p < 0.003). Furthermore, significant main effect was found for protocol on DJ height (p < 0.001) and time flight (p < 0.001). It is recommended to the sports experts to include similar condition stimuli in the warm-up procedure, in order to improve their jumping performance. Conclusive both CS cause PAP phenomenon but the specialized CS produces higher rates of improvements in young female artistic gymnasts.
... The height of rise of the center of mass in all jump tests was determined by the flight time according to the method of Asmussen and Bonde-Petersen 26 and used in order to analyze the explosive strength characteristics of the leg muscles as reported elsewhere. 27 Jump height, h, was calculated using h=g tf2/8, where t f is the flight time and g is the acceleration due to gravity (9.81 m•s -2 ). 28 with hands placed on their hips throughout the test. ...
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Article
BACKGROUND: Limited research exists examining the effect of different type of plyometric exercises (typical vs. specialized) that are employed as part of warm–up or as a strength–power potentiating complex. Thus, the purpose of this study was to examine the effects of a typical and a specialized plyometric protocol on the occurrence of post–activation potentiation (PAP) effects on drop jump (DJ) performance. METHODS: Thirty–five high level male and female artistic gymnasts participated in this investigation. All participants performed a DJ before and after two different conditioning stimuli; the first consisted of 10 repetitions of a specific gymnastic exercise (Rondat) and the second consisted of 2 set of 5 repetitions of tuc jumps. DJ height, contact time and leg power were assessed before, immediately after and at 3, 6, and 9 min following the conditioning stimulus. RESULTS: DJ height enhanced significantly in post measurements in male and female gymnast (P<0.05). Further, DJ contact time was significantly different immediately after, and after 6 and 9 min after the intervention in males (P<0.05), but only immediately after and after 9 min in female gymnasts (P<0.05). Gymnasts of both gender responded in a similar way to the interventions with male gymnasts showing greater potentiating abilities in DJ height compared to females (P=0.001). CONCLUSIONS: The results of the present study support that high level gymnast must include similar protocols in the warm–up procedures in order to improve their jumping performance.
... The reliability for the DJ height was estimated to be 0.93 (p< .001). The height of rise of the centre of mass in all jump tests was determined by the flight time according to the method of Asmussen and Bonde-Petersen (1974) and used in order to analyze the explosive strength characteristics of the leg muscles as reported elsewhere (Bosco et al., 1998). Jump height, was calculated using h = g tf2/8, Where tf is the flight time and g is the acceleration due to gravity (9.81 m . ...
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Article
The purpose of this study was to examine the post-activation potentiation effects of two different conditioning stimuli (Rondat and double tuck jumps) on drop jump height, Contact time, and Power; and to determine whether strong gymnasts are able to elicit post activation potentiation earlier than weaker gymnasts during a drop jump test in pre-adolescent female gymnasts. Twenty-nine moderately trained female gymnasts, aged 9 to 13 years old (age = 11.75 ± 1.31 years, body weight = 40.40 ± 10.84 Kg, body height = 147.87 ± 11.22 cm,) volunteered to participate in this study. Each subject performed a drop jump before, immediately after and 3, 6, and 9 minutes after two different conditioning stimuli; the first consisted of 10 repetitions of Rondat exercise and the second consisted of 2 set x 5 repetitions of double tuck jumps. According to the results both conditioning stimuli revealed consistent tendency for greater jump heights during the drop jump condition. The applied conditioning stimuli were not adequate to produce post-activation potentiation effect due to their low volume. The researchers therefore suggested that both conditioning stimuli could be added to a warm-up prior to either training efforts or prior to competitions in order to increase explosive power and jumping ability in preadolescent female gymnasts. However, changes must reach a certain threshold considering the exercises intensity and volume in order to lead to a beneficial outcome even to preadolescent gymnasts. © 2018, Editura Universitatii din Pitesti. All rights reserved.
... Dakota [47], while executing a 10 day exercise program at a frequency of 26 Hz, reported that WBV training resulted in an increase in neuromuscular adaptation, similar to the result that was produced by explosive strength exercises. Bosco et al. [48] also reported a significant improvement in the height and mechanical power, during a 5 seconds continuousjumping test, while investigating the effect of a 10 days WBV training program (5 × 90 seconds) at a frequency of 26 Hz. ...
Article
Background: Whole-body vibration (WBV) is a neuromuscular training method that has recently received popularity in health and fitness centers, as an additional or substitute method to conventional training and therapy, in order to improve muscle strength and power. Objective: The purpose of this review is to critically observe the effect of WBV training on neuromuscular performance in view of its ability to enhance the muscles strength, power, and flexibility; and also to investigate the influence of the different vibration characteristics (viz., method of application of vibration, frequency, and amplitude) and exercise protocols on the effect of this training. Method: For this review 24 studies or articles were examined, and based on exclusion and inclusion criteria, 5 studies were finally selected; and an attempt was made to uncover the factors influencing the improvement in neuromuscular performance as a result of WBV intervention. During the review, it was considered to include and discuss as many characteristics as possible, such as, knee extension, knee flexion, counter movement jump (CMJ), squat exercise, and jumping height (JH). Result: Whole-body vibration, along with additional exercise training, has a potential to induce substantial improvement in neuromuscular performance. Conclusion: Whole-body vibration can bring about improvement in muscles strength, power, and flexibility. The main factors associated with the improvement in muscles performance are range of amplitude and frequency, type of vibration and its method of application, training intensity, exercise protocol, and the characteristics of the participants.
... On the other hand vibration has some benefits as well which has been utilized and studied by different groups of therapists (Keller et al., 2000). Most importantly these benefits have been used for increasing the muscular strength in lower limbs or lower back (Bosco et al., 1999;Bosco et al., 1998;Issurin et al., 1994;Issurin and Tenenbaum, 1999). By these aspects, not all types of vibration can be expressed as a harmful index. ...
Thesis
Musculoskeletal Disorders (MSDs) are the common health problems among individuals in different occupations. Heavy truck drivers are exposed to various psychological, psychosocial and physiological factors such as Whole Body Vibration (WBV), awkward positioning, bad eating habits and etc. which some of them cause the prevalence of musculoskeletal discomfort in different body regions. In Iran, the prevalence of musculoskeletal discomfort among the heavy truck drivers is a mutual concern. Thus, investigation related to association of different factors with prevalence of musculoskeletal discomforts is necessary. Cross sectional study method is applied in order to assess association of factors with the occurrence of musculoskeletal discomforts. 384 Iranian heavy truck drivers are interviewed by an updated Nordic Musculoskeletal Questionnaire (NMQ). Furthermore, hypothesis testing is used to assess the associations of different factors and musculoskeletal discomfort reported by participants. Logistic regression method is used to investigate the different correlations among questions of the survey and different body sections that Interviewees experience trouble as well. Moreover, Rapid Entire Body Assessment (REBA) technique is applied for various positions of drivers whom used in order to fulfill different job tasks. Results demonstrate that 57% of the drivers are suffering from discomfort in their lower back region. Additionally, neck, left shoulder, right shoulder, knees and upper back, are among the high prevalence region that musculoskeletal discomfort has been reported. Hours of exposure to vibration were associated with discomfort of neck (p-value=0.00) and shoulders area (p-value=0.00); though, such a relation was not found for the discomfort of lower back (p-value=0.30). In addition 24 mathematical equations have been illustrated with significant predictors’ questions and their correlations with the prevalence musculoskeletal discomfort of different body regions of truck drivers. REBA method improved three different positions of the truck drivers; however, seating position behind the steering wheel is remains at high risk position category (REBA score=10).
... Whole Body Vibration (WBV) is a common exercise modality, used in fitness and health centers to increase muscle strength (Delecluse et al., 2003;Petit et al., 2010;Bosco et al., 1998;Mahieu et al., 2006;Giorgos et al., 2007;Savelberg et al., 2007;Luo et al., 2005), power (Luo et al., 2005;Adams et al., 2009), and flexibility (Fagnani et al., 2006;Dallas et al., 2012;Behm et al., 2011;Siegmund et al., 2014;Samson et al., 2012;Dadebo et al., 2004) in healthy humans. Vibration devices generate mechanical oscillation, which may affect the muscle spindles and Ia afferents, causing changes in the length of extrafusal fibers of muscles. ...
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Article
Aim: This study aimed to compare the effectiveness of whole body vibration (WBV) and local vibration (LV) exercise on counter-movement jump performance (CMJ) and its residual characteristics in well-trained athletes. Material and Methods: Thirty-two male athletes (age: 22.3±3.2 years) visited the laboratory twice, 48 hours apart, and performed WBV and LV in two sessions of equal duration. Each test day had two parts (sham [0 Hz, 0 mm] and vibration treatment [50 Hz, 4 mm]), 20 min apart. LV or WBV were applied for 6×15 sec with 1 min passive rest between repetitions. During the LV, participants were asked to lie supine (2×15 sec) and then lie laterally (2×2×15 sec) such that the quadriceps muscles connected to the WBV device. WBV was applied in the squatting position at 135º knee angle. After each session, the participants were tested for CMJ for 8 min at the 1st, 2nd, 3rd, 4th,6th, and 8th min. Results: The results of two-factor repeated measures ANOVA test revealed that both WBV (p = 0.27; np2 = 0.04) and LV (p = 0.57; np2 = 0.03) and their sham conditions decreased CMJ height to a similar extent. Further, there was no statistically significant difference between WBV and LV at any measurement time point (p>0.05). Conclusion: WBV and LV were not effective methods to enhance the CMJ performance of well-trained athletes. However, WBV platform can be safely used as LV exercise equipment since no adverse effect was observed.
... A corto plazo (9-10 días de entrenamiento) existen trabajos que han encontrado mejoras significativas en la potencia y el salto vertical (Bosco et al., 1998) y otros que no han encontrado significación estadística en las mejoras de salto o ninguna mejora en diferentes tests de velocidad y agilidad (Cochrane et al., 2004). ...
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Article
La exposición a vibraciones ha sido considerada tradicionalmente como perjudicial para el organismo humano. Sus efectos han sido estudiados de manera pormenorizada en medicina del trabajo habiéndose establecido incluso normativas ISO para evitar al máximo su aparición en los puestos de trabajo. Estas vibraciones suelen caracterizarse por su baja o muy alta frecuencia, su alta amplitud y la larga duración de su exposición al ser humano. Sin embargo, existen otras vibraciones que parecen provocar efectos beneficiosos en el organismo. En este caso, las frecuencias son moderadas (25-40 Hz), las amplitudes pequeñas (2-10 mm) y la duración de la exposición corta (inferior a los 30 minutos con intermitencias). En el presente texto se recogen fundamentalmente las aplicaciones de este método en campos como el entrenamiento deportivo, el fitness, la rehabilitación y la geriatría. De este modo, se incluye una revisión crítica de los estudios más relevantes así como la presentación de diferentes experiencias realizadas por los autores en los últimos cinco años
... During WBV, activation of the leg muscles varied between 12.6 and 82.4% of MVC values (Roelants, Verschueren, Delecluse, Levin, & Stijnen, 2006) and vibration occurring with gravitational changes to the body can reach up to 14 g (Bosco et al., 1999;Cardinale & Bosco, 2003). Muscle contraction and gravity provides a mechanical stimulus responsible for the development of muscle structure in exercise and training (Bosco et al., 1998). It has been hypothesized that low-amplitude, low-frequency mechanical stimulation of the human body is a safe and effective way to improve muscle strength (Cardinale & Bosco, 2003;Torvinen et al., 2002). ...
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Article
Background. The aim of the study was to investigate the acute effect of whole-body vibration (WBV) during heel raised and standing squat position on squat (SJ) and countermovement jump (CMJ) heights. Methods. Twenty four physically active sport science students are voluntarily participated in this study. Randomized, counterbalanced, crossover study was used in this study and all subjects completed two trials that were plantar (25–30°) and dorsal (5–10°) flexion squats. WBV exercises were performed on a vibration plate at 26 Hz frequency, 4mm amplitude. Jumping performances were assessed with and without WBV conditions. Subjects. executed WBV condition treatment on static plantar or dorsal flexion half squat position (45°knee angle) for 3x60 s with 60 s rest between sets. Results. There was no statistically significant two-way interaction between treatments and times for SJ and CMJ (p > .05). SJ and CMJ after the WBV were significantly higher than without WBV condition (p < .05). SJ and CMJ heights were higher than baseline values without WBV. Conclusion. These results indicate that there were no differences between WBV during plantar and dorsal flexion squat position on SJ and CMJ heights. Regardless of different muscle length squat position during WBV, there were little but significant differences (~1cm) on SJ and CMJ heights after WBV. According to these results it can be said that WBV had a statistically significant acute effect on jumping, but different plantar-flexor muscle length squat position on vibration plate during WBV did not have any effect on jumping performance.
... During WBV, activation of the leg muscles varied between 12.6 and 82.4% of MVC values (Roelants, Verschueren, Delecluse, Levin, & Stijnen, 2006) and vibration occurring with gravitational changes to the body can reach up to 14 g ( Bosco et al., 1999;Cardinale & Bosco, 2003). Muscle contraction and gravity provides a mechanical stimulus responsible for the development of muscle structure in exercise and training (Bosco et al., 1998). It has been hypothesized that low-amplitude, low-frequency mechanical stimulation of the human body is a safe and effective way to improve muscle strength (Cardinale & Bosco, 2003;Torvinen et al., 2002). ...
Article
Background. The aim of this study was to explore junior tennis coaches’ insights in relation to teaching styles they employ as well as the motivations and reasons that underpin these practices. Methods. The research consisted of implementing interviews with the 13 tennis coaches. It employed purposive or theoretical sampling. Semi-structured interviews commenced with a prearranged group of questions to permit scope in direction so that the interviewer may follow what is considered as pertinent to the interviewee. The coaches were filmed during three 30 minute sessions. Prior to the interviews, each of the coaches was requested to view a portion of their video-recorded sessions. The interview data were analysed via deductive content analysis. Results. The results highlighted a lack of knowledge concerning the theoretical and practical application of various teaching styles required for coaching tennis to junior players. The coaches lacked self-awareness with regard to their own coaching performance and were incapable of accurately describing the reasons why they implement particular ways of coaching. Coaches used an assortment of terms to identify the way they coach and that their decision to employ certain ways of coaching did not alter as a function of the age group, skill level or ability of the players they were coaching. Observing and/or discussing aspects of coaching with a mentor as well as playingexperience had a greater influence on current coaching behaviour than attending an accreditation course. Conclusion. The finding from this study is that the personally anticipated coaching behaviour of the coach was not what they realised upon observation of their coaching.
... With the emergence of whole-body vibration (WBV), the question of the efficacy of a protocol of this nature for improving performance has arisen (21). Previous studies have found significant improvements in neuromuscular performance and force output, as well as, increased muscle temperature and circulating hormone concentrations after acute exposure to vibration (1,2,5,6,(8)(9)(10)(11)14,18,19,(23)(24)(25)(26). In recent years, several studies have found that WBV warm-up can improve exercise performance (3,4,7,28), although not all studies investigating WBV warm-up reported an effect on performance (12,17). ...
Article
The warm-up routine preceding a training or athletic event can affect the performance during that event. Whole-body vibration (WBV) can increase muscle performance, thus the inclusion of WBV to the warm-up routine might provide additional performance improvements. The purpose of this investigation was to examine the acute effect of a WBV warm-up using a vertical oscillating platform and a more traditional warm-up protocol on feet quickness in physically active men. Twenty healthy and physically active men (18-25 y, 22 ± 3 y, 176.8 ± 6.4 cm, 84.4 ± 11.5 kg, 10.8 ± 1.4 % body fat) volunteered for this study. A 2×2 factorial design was used to examine the effect of four warm-up scenarios (no warm-up, traditional warm-up only, WBV warm-up only, combined traditional and WBV warm-up) on subsequent 3-second Quickfeet Count Test (QFT) performance. The traditional warm-up consisted of static and dynamic exercises and stretches. The WBV warm-up consisted of 60 seconds of vertical sinusoidal vibration at a frequency of 35 Hz and amplitude of 4 mm on a vibration platform. The WBV protocol significantly (p ≤ 0.0005, η = 0.581) augmented QFT performance (WBV: 37.1 ± 3.4 touches; no-WBV: 35.7 ± 3.4 touches). The results demonstrate that WBV can enhance the performance score on the QFT. The findings of this study suggest that WBV warm-up should be included in warm-up routines preceding training and athletic events which include very fast foot movements.
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Article
This study involved the application of static stretching exercises in warm-up part of soccer training with vibration stimulus (VSI), compared to an equivalent stretching exercise without applying vibration (SSI). For this purpose, all subjects, are in a randomized manner selected in two equal groups (SSI and VSI). Complete treatment for both groups lasted four weeks (3 x per week). VSI group has implemented an identical training as SSI group, with difference that all exercises performed on the platform (f = 40 Hz, A = 2 mm). Results of the combined analysis of variance, indicating that there is a statistically significant interaction (p<0.05) on variables to assess range of motion, in addition to the variable to assess range of motion in the position of plantar flexion (p = .079). Results of muscle function of lower limbs showed no differences between the study groups (p<0.05). The results of this study suggest that in chronic settings, static stretching with vibration have the potential to cause a substantial increase in range of motion, but without significant improvement of muscle function (jumping and sprinting).
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Conference Paper
The aim of this study was to investigate 3-days intensive whole body vibration (WBV) exposure on activation strategies of lower extremity muscles. For this purpose, six male athletes’ dominant leg muscles (Tibialis Anterior (TA), Gastrocnemious Medialis (GM), Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF)) were recruited voluntarily. Before the trails their baseline electromyography (EMG) values were taken for reference evaluation. After that, they were trained static semi-squat position with 120o knee flexion angle on vibration platform (vertical vibration; 4 mm(high),30 Hz), during 3 days. The subjects were exposed to vibration 6 times for duration of 60 seconds with a 2 minutes rest between each treatment. Consequently, 3 days intensive WBV exposure caused a progressive increase in EMG activity (P<0.05).
Article
Stimulation of vibratory stimuli is another measure in physiotherapeutic and sports training. Particularly the interest in research has significantly increased in the field of biomechanics and sports training. The basic subject of the research is the effects of stimulation with vibratory stimuli in relation to motor strength, coordination properties and mobility. The aim of the work is to discuss the parameters of stimulation and to review the biomechanical and physiological effects of using the whole body vibration on the human motor skills.
Chapter
This chapter describes a new method for pinpointing the latency of the vibration-induced muscular reflex. To determine the reflex latency, the vibration-altered electromyography (EMG) and acceleration data were spike triggered and averaged using the tip of the EMG response as the trigger. Averaged results belonging to several different vibration frequencies were then superimposed to achieve a ‘cumulative averaged record’. The lowest standard error of the cumulative averaged record for the acceleration data was marked to indicate the effective stimulus point on the vibration cycle. Similarly, the lowest standard error of the cumulative averaged record for the EMG data showed the start of the reflex response. The time between the effective stimulus point and the start of the reflex response on EMG data was designated as the ‘reflex latency’ of this circuit. Using this technique, we have examined the latency of whole-body vibration (WBV)-induced reflexes. We found that the WBV induced two different reflex responses depending on the vibration amplitude. While low amplitude WBV (0.1–0.4 mm) produced short latency reflex similar to muscle spindle-based T-reflex (34 ms), high amplitude vibration (1.1–2.8 mm) generated long latency reflex response (44 ms) which may have a different receptor origin than the spindles. We have also summarized the modulatory effects of vibration on spindle-based reflexes and indicated that these reflexes are reduced during and/or following vibration. It is suggested that this effect may originate from the reduction in effectiveness of the spindle synapses on motoneurons via premotoneuronal means.
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Article
Whole body vibration training (WBVT) has been considered as a new method of training that resulted in mechanical stimulation of neuromuscular system. Regarding to the high relationship between neuromuscular system efficacy and dynamic balance that it is an avoidable part of daily activity and sports skill, the purpose of this study was to examine the effect of whole body vibration training on dynamic balance in male athletic students. Twenty male athletic students from the departments of physical education and sport science of university of Tehran (age: 20.7±1.03 y, weight: 69.25±6.21 kg, height: 174.5±5.05 cm, BMI: 22.58±3.1) participated in this study while they divided in two control and experimental groups. The dynamic balance measured with the star excursion balance test (SEBT) before applying WBVT. Experimental group participated in whole body vibration training for 10 days (frequency 30 Hz, amplitude 10 mm and in five different body position). Afterward exercise duration in each position started with 90 seconds vibration and 40 seconds rest. Each day exposure duration of each position increased five seconds, which in the end of training program, duration exercise reached up to two minutes. The post-test of SEBT done for two groups afterward. MANOVA, a two way repeated measure ANOVA and dependent t test used to analyze the data. Significant differences shown for dynamic balance after WBVT in five excursions (medial, antromedial, posterior, potrolateral and postromedial). Two groups had a significant difference when all excursions compared in a time. An improvement shown in five excursions (medial %4.69, antromedial %4.3, posterior %8.6, potrolateral %6.22 and postromedial %7.9). WBVT could improve dynamic balance specifically in medial, antromedial, posterior, potrolateral and postromedial excursions. However, further evaluation need to be done before prescribing it as neuromuscular training method examined it further to use it as a new method of neuromuscular training.
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Article
Efectos de un entrenamiento vibratorio sobre la actividad del rectus abdominis y sobre la transmisión de aceleraciones durante la realización de un puente frontal Effects of whole body vibration on rectus abdominis activity and transmission of accelerations during a front bridge exercise Durante las dos últimas décadas se ha incrementado notablemente la utilización de la vibración como medio complementario de ejercicio físico. La literatura científica muestra distintos efectos positivos, aun-que la mayor parte de ensayos se han centrado en el análisis del ejercicio de squat. El objetivo del pre-sente estudio fue analizar la actividad muscular del rectus abdominis y la transmisión de la vibración en el cuerpo humano durante la realización de un puente frontal sobre una plataforma vibratoria oscilante vibrando a diferentes frecuencias (5, 16, 20 Hz) y a una amplitud constante (3 mm). Las aceleraciones máximas en la cabeza (ejes X, Y, Z) y la actividad electromiográfica media del rectus abdominis fueron determinadas en 31 sujetos sanos por medio de un acelerómetro triaxial y electromiografía de superficie. Para cada eje se calculó un coeficiente de amortiguación restando la aceleración máxima registrada en la cabeza a la aceleración máxima registrada sobre la plataforma. La actividad electromiográfica del rectus abdominis y los coeficientes de amortiguación en los ejes X y Z aumentaron significativamente con cada incremento en la frecuencia de vibración de la plataforma (p < 0.001). Se concluye que el puente frontal sobre plataforma vibratoria a las frecuencias de 16-20 Hz constituye un ejercicio eficaz para reclutar las fibras musculares del rectus abdominis en la población de estudio. Palabras claves: vibración corporal; aceleración; electromiografía; puente frontal. R e s u m e n Whole-body vibration exercise have been widely used during the last two decades, with most scientific publications reporting various positive effects. Most commonly, squat exercises have been studied. Instead, this study explored the rectus abdominis activity and the transmission of sinusoidal vibration to the human body during the performance of front bridges on a oscillating vibration platform at different frequencies (5, 16, 20 Hz) with constant amplitude (3 mm). Maximal vibration-induced accelerations at the head (axis X, Y, Z) and mean electromyographic activity were assessed in thirty-one healthy subjects using a skin-mounted triaxial accelerometer and surface electromyography. A damping coefficient was calculated for each axis as the difference between platform and head maximal accelerations. Rectus abdo-minis activity and the damping coefficients in the axis X and Z significantly increased with each increment in the platform vibration frequency (p < 0.001). It is concluded that a front bridge on an oscillating vibration platform vibrating at 16-20 Hz is effective to activate significantly the rectus abdominis muscles in the studied population.
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Journal of Sport in Biomotor Sciences, Volume 5, Number 1, 2012 Effects of acute eccentric exercise on serum vascular endothelial growth factor and endostatin concentration in male wistar rats Nourshahi M 1, Feizemilani R 1, Gholamali M 2 1.Shahid Beheshti University 2.MSc student of Shahid Beheshti University Received: 01/12/2011 Correspondence: Maryam Nourshahi, Shahid Behashti Universtiy, Velenjak, Tehran, Iran, Email: M-Nourshahi@sbu.ac.ir Revised: 31/01/2012 Abstract Accepted: 10/04/2012 Introduction: Angiogenesisis the formation of new blood vessels from an existing vascular bed. This process can facilitate the oxygen delivery to active muscles. Studies have shown that acute exercise can affect the process of angiogenesis. However, the role of the type of contraction that is used in exercise, especially eccentric contraction, in angiogenesis process is not yet clear. Purpose: The aim of this study was to investigate the effect of eccentric exercise on serum levels of vascular endothelial growth factor (VEGF) and Endostatin in male wistar rats. Materials and Methods: 36 male wistar rats (age= 49±7 , weight=290±10 ) were used in this study. The rats were divided into two groups: the experimental group (eccentric exercise group) (n = 24) and the control group (n = 12). Also, the experiment group was subdivided immediately after the exercise (n = 12) and 24 hours after the exercise (n = 12). The eccentric exercise involved running on a treadmill with the speed of 20 m/s and -160 slopes for 45 minutes. Immediately and 24 hours after the exercise, blood sample was drawn from the descending aorta for measurement of serum VEGF and endostatin. Serum VEGF and endostatin were measured by ELISA method. Results: Results of the study showed that immediately and 24 hours after the exercise the serum levels of VEGF decreased 28% and 12%, respectively (p≤0.05) Also, serum levels of endostatin decreased 26% and 38%, immediately and 24 hours after the exercise, respectively (p≤0.05). Additionally, VEGF/endostatin ratio decreased immediately after the exercise (p=0.02) and increased significantly 24 hours after the exercise (p=0.001). Discussion and Conclusion: The finding of this study showed that the main factors that are involved in angiogenesis decreased significantly immediately after the eccentric exercise This finding may provide new insights into better comprehension of mechanisms related to changes of capillary density in response to eccentric training. Keywords: Eccentric exercise, VEGF, Endostatin, Male wistar rat.
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Article
Background: It has been shown that whole body vibration training has an effect on strength and balance in athletes of various sports.Objective: The purpose of the study was to examine the effect of 8 weeks of Whole Body Vibration (WBV) training on static balance and explosive strength of the lower limbs, using two different training intensities vibration protocols.Methods: Eighty-three physical education students (age 19.39 ± 2.35 years) volunteered to participate in an 8-week WBV training. They were randomly divided into two groups with 30 sec and 60 sec duration of vibration exposure per exercise, total volume of exercise was the same for both groups. The explosive strength of the lower limbs was assessed by a squat jump and static balance by Balance Error Scoring System at the baseline (pre-test) and after 8 weeks of WBV training at 15 sec, 5, 10, and 15 min after the end of WBV exposure. A two-way ANOVA 2 × 5 (protocol × time) with repeated measures on both factors was used. Univariate analyses with simple contrasts across time were selected as post hoc tests.Results: Results showed a time × protocol interaction effect for static balance (p < .001) but not for the squat jump (p > .05). Furthermore, a time effect was found for the static balance and squat jump test. The 60 sec protocol had a greater percentage improvement compared to the 30 sec protocol in static balance (p = .003), whereas the 30 sec protocol was superior to the 60 sec protocol in explosive strength. However, the differences between the two protocols were not significant.Conclusion: WBV training had positive effects on static balance and explosive strength in physical education students. Balance and jump performance may benefit from WBV training. Therefore, WBV may be an effective training method for the improvement of static balance and lower limb strength.
Article
In this study, the researchers examined the changes that took place in the somatosensory cortex area in the brain when subthreshold mechanical vibratory stimulation was applied to the lower limb of the elderly. For this, a subthreshold vibratory stimulation of 190 Hz as applied to the tibialis anterior tendon, and the Electroencephalography was measured. In order to examine the changes in the somatosensory cortex, the amplitude of the Somatosensory Evoked Potentials (SEPs) was analyzed. When the subthreshold vibratory stimulation was applied to the tibialis anterior tendon, the SEPs amplitude was increased more than the amplitude under none stimulation setting. This result means that the subthreshold mechanical vibratory stimulation may affect the nervous system of the elderly.
Article
The purpose of this study was to investigate the effects of vibration exercise using surface electromyography. Seven male collegiate wrestlers were participated in this study. Each subject stood on the platform and the vibration was induced for 1min. WEMG8 EMG system was used to record muscle activity from Vastus lateralis, Biceps Femoris, Tibialis Anterior, and Gastrocnemius. The EMG data were sampled for 30 sec. during non-vibration and vibration half squat position, respectively. The raw data were band pass filtered to remove noise and full wave rectified Paired sample t-test were performed to see the differences of maximum and average EMG between non-vibration and vibration trials. The results indicated that vibration produced much more muscle contraction than that of non-vibration trial for all selected muscles even though the significant difference was found only from Biceps Femoris. This phenomenon was due to the individual differences so care must be taken to evaluate vibration intensity and position before personal training.
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Book
CONTENTS Keynote Papers................................................................................................................................... History of Thermology and Thermography: Pioneers and Progress (Ring EFJ)................3 Thermography in Plastic Surgery (Mercer JB, de Weerd L, Weum S)................................9 Thermography in Viticulture (Grant OM)............................................................................16 OralPresentations....................................................................................................................Papers.................................................................................................................................... Accuracy When Assessing and Evaluating Body Temperature in Clinical Practice: Time for a Change? (Sund-Levander M, Grodzinsky E)............................................................25 Core Body Temperature Evaluation: Suitability of Measurement Procedures (Quelhas Costa E, Guedes JC, Baptista JS).....................................................................................33 Potential Errors in Mean Skin Temperature Calculation Due to Thermister Placement as Determined by Infrared Thermography (Pascoe DD, Barberio MD, Elmer DJ, Laird Wolfe RH)......................................................................................................................................42 Using a Climatic Chamber to Measure the Human Psychophysiological Response Under Different Combinations of Temperature and Humidity (Guedes JC, Quelhas Costa E, Baptista JS)........................................................................................................................................49 Application of Cold Provocation for Breast Cancer Screening Using IR Thermography (Lääperi E, Lääperi A-L, Strakowska M, Wiecek B, Przymusiala P)..........................................................................................................................................55 The Effect of Whole-body Vibration in the Skin Temperature of Lower Extremities in Healthy Subjects (Seixas A, Silva A, Gabriel J, Vardasca R)......................................................................................................................................59 Using Clinical Thermography as Diagnostic Complementary Procedure for Hand Arm Vibration Syndrome (Vardasca R, Ring EFJ, Plassmann P, Jones CD, Gabriel J)..................................................................67 Screening Fever, A New Approach (Cardoso A).....................................................................................................76 Integrating Medical Thermography on a RIS Using DICOM Standard (Vardasca T, Martins HMG, Vardasca R, Gabriel J).................................................................................................79 Histographic Method as a Tool of Thermal Image Processing (Benkö I, Köteles GJ).........................................82 Thermographic Examination for Hypothermia (Usuki H, Tai C, Hamano T, Kondo A, Sakabe M, Nishimura M, Asano E, Ohshima M, Kashiwagi H, Nishizawa Y, Yamamoto N, Akamoto S, Fujiwara M, Okano K, Suzuki Y)...88 Scrotal Infrared Digital Thermography for Detection of Subclinical Varicocele (Gabrielli D, Cardone D, Di Donato L, Pompa P, Cotroneo AR, Romani GL, Merla A).............................................91 The Highly Focalized Thermotherapy in the Treatment of Solid Tumors: Temperature Monitoring Using Thermography (Portela A, Vasconcelos M, Silva A, Gabriel J, Cavalheiro J).....................................................,,..95 Thermography as an Alternative Tool to Determine Pressure Distribution on the Stump of Transfemoral Amputees (Mendes E, Silva A, Correia R, Crisóstomo C, Vaz F, Gabriel J)...........................................................99 Thermal Effect during Ketamine Anesthesia in Laboratorial Mice (Ribeiro P, Silva A, Antunes L, Gabriel J)................................................................................................................105 Thermography of Facial Skin Temperature in Healthy Subjects During Cooling of the Face with Hilotherapy (Howell KJ, Collier JM).......................................................................................................................110 Infrared Thermography in Plastic Surgery: A Comparative Study of Pre and Post - Operatory Abdominal Skin Circulation after Different Techniques – The Effect of Undermining Vicari Nogueira CHF, Barros CF, Scherdel EP, Nerin JPB, Brioschi ML)...............................................................114 Infrared Thermography Assessment of Infantile Hemangioma Treatment by Propranolol (Kalicki B, Jung A, Ring F, Rustecka A, Maślany A, Żuber J, Murawski P, Bilska K, Woźniak W)........................117 Facial Imprints of Autonomic Contagion in Mother and Child: A Thermal Imaging Study (Ebisch SJ, Aureli T, Bafunno D, Cardone D, Manini B, Ioannou S, Romani GL, Gallese V, Merla A)...................121 Reliability and Reproducibility of Skin Temperature of Overweight Subjects by an Infrared Thermography Software Designed for Human Beings (Fernández-Cuevas I, Marins JC, Carmona PG, García-Concepción MA, Arnaiz Lastras J, Sillero Quintana....130 Thermographic Evolution of Bone Temperature Evolution (Ribeiro TP, Silva A, Gabriel J).................................138 Effect of Yoga and Swimming on Body Temperature of Pregnant Women (Sillero-Quintana M, Conde-Pascual E, Gomez-Carmona PM, Fernandez-Cuevas I, García-Pastor T)..............143 Legality Associated with the Use of Infrared Thermal Imaging in Veterinary Medicine (Purohit RC, Schumacher J, Pascoe DD, Caldwell JM, Wolfe DF).......................................................................150 The Use of Thermography to Evaluate Back Musculoskeletal Responses of Young Racehorses to Training (Soroko M, Jodkowska E, Zabłocka M)................................................................................................................152 Effect of High Regional Nerve Blocks on the Thermographic Patterns in the Limbs of Horses (Schumacher J, Aswani K, Pascoe DD, Purohit RC).............................................................................................157 Thermography and Oral Pathology (Mostovoy A).................................................................................................159 Poster Presentation Papers Infrared Imaging of the Crânio-Cervico-Mandibular Complex in Bruxism Patients (Castro V, Clemente M, Silva A, Gabriel J, Pinho.J)...............................................................................................162 Evaluation of the Masticatory Muscles Temperature by Thermal Imaging During Mastication (Barbosa L, Clemente M, Silva A, Gabriel J, Pinho J)............................................................................................166 Diagnostic Evaluation of Chronic Venous Insufficiency Cases Using Thermal Imaging (Martins MCF, Ribeiro LMF, Cury J)........................................................................................................................169
Article
Infrared Precision agriculture matches inputs to crop demands, enhancing crop yields and product quality, of-fering economic benefits to the producer, and reducing resource wastage and pollution. Dwindling water resources make precision irrigation an area of particular interest. Precision irrigation is especially appealing in viticulture, where precise regulation of vine water status is necessary to optimize yield and grape (and hence wine) quality simultaneously. Precision irrigation requires monitoring of both spatial and temporal variation in vine water status. Closure of stomata, the pores on the leaf surface through which gas exchange takes place, is a rapid response to water deficit. Detection of stomatal closure could alert the viticulturist to the need to irrigate. Monitoring stomatal aperture, however, until recently was a very slow process. When stomata are open, transpiration cools the leaves, but when the stomata close, there is no longer any stomatal cooling. As a result, leaf temperature is a good indicator of transpiration rate or stomatal conductance, or conversely of water stress, when environmental conditions are constant. Much progress has been made in determining the impact of a range of variables (meteorological, leaf surface radiative properties etc.) on leaf temperature. This means that even under varying environmental conditions, stomatal conductance can now be estimated from leaf temperature. Thermal imaging means that the temperature of large numbers of leaves, plants, rows of crops, or even whole fields can be assessed rapidly. Therefore in theory it should be possible to use thermal imaging to detect individual vines that require irrigation, and to determine changing irrigation requirements over time. In practice, there is still some way to go before thermal imaging is used routinely for irrigation scheduling. Whole crops do not behave identically to individual leaves, variation in temperature caused by variability in crop structure can be difficult to separate from variation caused by differences in transpiration, and the best means of removing the effect of variation in meteorological conditions is still unclear. There are additional challenges relating to grapevine. Firstly, it is not a continuous crop, meaning that in overhead images leaf temperatures need to be separated from the temperatures of the soil or ground herbage in corridors between vine rows. Secondly, for many cultivars understanding of grapevine physiology has been derived from measurement on the vertical leaves facing into the corridors, whereas aerial or satellite imaging captures horizontal leaves at the top of vine canopies. Nonetheless, grapevine is one of the best studied crops with respect to thermal imaging under field conditions, and the potential of thermal imaging for detection of spatial variation in vine water status has been amply proven. With sufficient focusing of effort and collaboration between disciplines, the remaining technical problems should not be insurmountable. There has recently also been some interest in utilizing thermal imaging to better understand different physiological responses in different cultivars, and there is no reason why thermal imaging could not be used for large-scale screening of different genotypes under particular environmental conditions, as is being undertaken as part of genetic improvement programs in other crops. Thermal imaging has also been shown to be useful for pre-visualization detection of pathogen infection and for monitoring the temperature of developing grapes (an important determinant of final grape, and wine, quality). Diverse uses of thermal imaging in other disciplines, such as ecology, may also be found to be relevant to enhancing modern viticulture. Additionally, it is likely that thermography will increasingly be combined with other imaging techniques (near infra-red, chlorophyll fluorescence, multi/hyperspectral, laser-induced) for a more complete understanding of vine, or vineyard, behaviour.
Article
Whole body vibration (WBV) has been used as an adjunctive therapy to improve the strength and size of paraspinal muscles as well as postural control in people with lower back pain. It has been proposed that activation of the m. multifidus plays a key role. As the function and anatomy of the m. multifidus in the horse is comparable to that in man, the authors investigated whether WBV might also be a valuable physiotherapeutic modality in horses. The effects of WBV on the cross-sectional area (CSA) and left to right symmetry of the m. multifidus at various locations of the thoracolumbar spine of the horse was evaluated in a single-subject quasi-experimental time-series design with repeated measure. Nine horses were subject to WBV, 30 min, twice daily, 5 days a week, for 60 days in addition to their regular exercise routine. The CSA of the left and right m. multifidus was measured ultrasonographically at four levels (T15–T16, T16–T17, T18–L1 and L1–L2) along the thoracolumbar spine at Days −30, 0, 30 and 60 of the study. Changes in the CSA and CSA symmetry (left to right) of the m. multifidus were analysed using nonparametric, repeated measures, comparison of mean ranks with post-hoc analysis as necessary. A significant increase (P<0.05) in m. multifidus CSA was found at all spinal levels after 30 and 60 days of WBV and a statistically significant improvement in m. multifidus symmetry (becoming more symmetrical) was found after 60 days of WBV, indicating that WBV may be a valuable alternative to dynamic mobilisation exercises when an increase in size and improvement in left to right symmetry of the m. multifidus is sought.
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Article
OBJETIVOS: O objetivo deste estudo é analisar a influência da Plataforma Vibratória no desempenho do salto vertical de atletas de futebol. MATERIAIS E MÉTODOS: A amostra foi composta de 30 atletas de futebol do sexo masculino, idade (18,57 ± 0,81 anos), peso (75,49 ± 7,463 kg), altura (1,79 ± 0,057 cm), percentual de gordura corporal (9.6 ± 1,327%) e IMC (22,89 ± 1,354 kg/m2) alocados aleatoriamente em Grupo 1 (VCI) e Grupo 2 (CIQ). Valores de p < 0,05 foram considerados estatisticamente significativos. RESULTADOS: A altura do CMJSBB aumentou significativamente (p = 0,0001) após ambas as intervenções (VCI e CIQ), reduzindo também de forma significativa no período de follow-up (p = 0,0003). Não houve diferença significativa entre os grupos em todos os períodos (p = 0,524). No CMJCBB, houve um aumento significativo na altura do salto ao se comparar o grupo antes e depois das intervenções por VCI e CIQ (p = 0,001) e uma diminuição significativa comparando as medidas após as intervenções com o follow-up. Em relação aos tratamentos (G1 vs G2) não houve diferença estatística entre eles em todos os períodos (p = 0,675). DISCUSSÃO: De acordo com os resultados, houve diferenças em relação ao fator tempo (pré, pós e follow-up). No entanto, não foram observadas mudanças em relação aos tratamentos propostos ao G1 e ao G2. O período de exposição de quatro semanas de VCI não produziu ganhos adicionais nas características morfológicas e/ou nas propriedades neuromusculares em longo prazo no G1 quando comparados com o G2. CONCLUSÃO: O treinamento por VCI pode ser introduzido com fins complementares à rotina de treinamento de atletas de futebol, objetivando a melhora do desempenho muscular nos membros inferiores atribuídos de forma quantitativa na capacidade de saltar desses indivíduos.
Article
The Mechanisms of whole body vibration on the human body is not clearly presented despite of the research result and there is not enough research that shows the effects of vibration on the kinetic changes of the lower joint. Therefore, this study focuses on finding out which lower joint is related with kinetic vertical jump ability. Five male and five female who didn`t have orthopedic history were selected as the subjects. The subjects carried out three squat jumps before and after 5minutes of 30Hz whole body vibration. We have utilized a 3D motion analysis system to analyze the kinetic changes of the lower joint in the vertical jump. The height of subjects squat jump was improved after whole body vibration treatment. Also, the lower joint moment and power increased. However, there were no statistically significant changes in GRF, hip joint moment and power after the whole body vibration proved to have positive effect on the ankle and knee joints but showed negative effect on the hip joint.
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Article
Purpose: The purpose of this study was to determine the effectiveness of whole-body passive vibration exercise and its differences from aerobic exercise on body composition, bone mineral density (BMD) and bone mineral content (BMC). Methods: Obese middle-aged women (n=33 out of 45) with 34±3% body fat completed the training protocol. They were randomly assigned into diet (n=9; control group), diet plus whole-body vibration exercise (n=13; vibration group), and diet plus aerobic exercise (n=11; aerobic group) groups and we compared their body composition, BMD, and BMC before and after 9 months of training. There were no significant differences in nutrient intake among groups during the training period. Results: Relative body fat (%) decreased significantly (p < .05) in all three groups and the exercise groups showed a greater reduction in fat mass than the diet only group. BMD in the whole body, lumbar spine, hip and forearm were not significantly different among the three groups. Total body BMC increased significantly in the vibration group throughout the first 6 months of training. Conclusion: Results suggest that long- term vibration training when used in conjunction with a diet program is as effective as aerobic exercise with a diet program in improving body composition of obese middle-aged women without compromising BMC or BMD. Thus, it can be considered a novel and effective method for reducing body fat.
Chapter
Zunächst kann konstatiert werden, dass Sportgeräte an die verschiedenen Anforderungen und Situationen angepasst werden müssen. Dies betrifft die einzelnen Bereiche des Sports, wie den Leistungssport, die verschiedenen Facetten des Breitensports und den Rehabilitationssport. Unterschiedliche Anforderungen des Breitensports stellen bspw. der Sport mit Übergewichtigen und Senioren dar. Beispiele hierfür werden vorgestellt. Verschiedene Sportschuhkonzepte zeigen, wie durch diese wiederum die Bewegung beeinflusst werden kann. Weitere Schwerpunkte des Kapitels sind die Einbeziehung ergonomischer Gesichtspunkte, des Komforts und der Sicherheit. Es wird erläutert, wie physikalische Effekte zur Steigerung des Trainingseffektes (z. B.: Vibrationstraining) und zur Optimierung der Sportgeräte genutzt werden können. Auf Grund der zunehmenden Technologisierung werden immer öfter auch Mess- und Informationssysteme in die Geräte eingebaut. Auf der Grundlage von praktischen Beispielen werden hierfür allgemeine Hinweise gegeben.
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The purpose of this study was to evaluate the predictive power of physiological tests in categorizing competitive alpine skiers. Sixty-one subjects (30 female and 31 male) were classified into three levels: international, national, and regional on the basis of past competition results. Hydrostatic weighing, maximal cycling, Wingate, 60-s repeated jump, and vertical jump tests were used to assess body composition, aerobic and anaerobic power, respectively. MANOVA revealed a significant group by gender interaction (Hotellings T, p less than .001), and main effects of gender and group (p less than .001). Discriminant analyses performed separately for male and female groups determined which variables were responsible for differences and resulted in selection of the following variables for classification of the men: average work from the repeated jump, absolute power for the vertical jump, and Wingate endurance. For the women, average work from the repeated jump, absolute and relative vertical jump power, absolute maximum Wingate power, and relative repeated jump power were most important. Fat-free mass was a powerful predictor for both sexes because of its strong relationship (r greater than 0.85) with power results. Aerobic power was not useful in group classification. In conclusion, physiological tests of anaerobic power and fat-free mass were the best predictors of group membership.
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The activities of single proprioceptive fibres were recorded from the lateral peroneal nerve using transcutaneously implanted tungsten microelectrodes. Unitary discharges originating from muscle spindle primary and secondary endings and Golgi tendon organs were identified by means of various physiological tests. The sensitivity of proprioceptors to mechanical vibrations with a constant low amplitude (0.2-0.5 mm) applied at various frequencies to the tendon of the receptor-bearing muscle was studied. Muscle spindle primary endings (Ia fibres) were found to be the most sensitive to this mechanical stimulus. In some cases their discharge could be driven in a one-to-one manner up to 180 Hz. Most of them also fired harmonically with the vibration up to 80 Hz and then discharged in a subharmonic manner (1/2-1/3) with increasing vibration frequencies. Muscle spindle secondary endings (II fibres) and Golgi tendon organs (Ib fibres) were found to be either insensitive or only slightly sensitive to tendon vibration in relaxed muscles. The effects of tendon vibration on muscle spindle sensory endings response to muscle lengthening and shortening induced by imposed constant velocity or sinusoidal movements of the ankle joint were studied. Modulation of the proprioceptive discharge frequency coding the various joint movement parameters was either completely or partly masked by the receptor response to vibration, depending on the vibration frequency. Moreover, vibrations combined with sinusoidal joint movements elicited quantitatively erroneous proprioceptive messages concerning the movement parameters (amplitude, velocity). The sensitivity of the Golgi tendon organs to vibration increased greatly when the receptor-bearing muscle was tonically contracted. These data confirm that vibration is able to preferentially activate the Ia afferent channel, even when the vibration amplitude is low. They define the frequency sensitivity of the muscle spindle primary and secondary endings and the Golgi tendon organs. They also show that the physiological messages triggered by ongoing motor activities undergo a series of changes during the exposure of muscles to vibration.
Article
The characteristics of EMG structure are studied for the voluntarily contracting human m. soleus against the background of vibrational stimulation. Averaging over the vibration cycle and spectral analysis are used. Averaging reveals EMG nonuniformity over the cycle; narrow peaks appear in the spectrum at the vibration frequency. EMG analysis proves informative at high vibration frequencies (70–120 Hz), while analysis of the rectified EMG proves informative at low frequencies (30–70 Hz). In the case of tibial ischemic blockade the peak disappears earlier than the tendon reflex. As the force increases, the peak amplitude normalized to the EMG power decreases. The peak rises with prolonged contraction under vibration. These effects are thought to reflect the changes in the relative contribution to the stimulating influx to the motoneurons of the part which is delivered via short connections from the muscle receptors.
A simple test for the measurement of mechanical power during a vertical rebound jump series has been devised. The test consists of measuring the flight time with a digital timer (0.001 s) and counting the number of jumps performed during a certain period of time (e.g., 15–60 s). Formulae for calculation of mechanical power from the measured parameters were derived. The relationship between this mechanical power and a modification of the Wingate test (r=0.87, n=12 ) and 60 m dash (r=0.84, n=12 ) were very close. The mechanical power in a 60 s jumping test demonstrated higher values (20 WkgBW–1) than the power in a modified (60 s) Wingate test (7 WkgBW–1) and a Margaria test (14 WkgBW–1). The estimated powers demonstrated different values because both bicycle riding and the Margaria test reflect primarily chemo-mechanical conversion during muscle contraction, whereas in the jumping test elastic energy is also utilized. Therefore the new jumping test seems suitable to evaluate the power output of leg extensor muscles during natural motion. Because of its high reproducibility (r=0.95) and simplicity, the test is suitable for laboratory and field conditions.
To investigate the influence of skeletal muscle fiber composition on the mechanical performance of human skeletal muscle under dynamic conditions, 34 physical education students with differing muscle fiber composition (M. vastus lateralis) were used as subjects to perform maximal vertical jumps on the force-platform. Two kinds of jumps were performed: one from a static starting position (SJ), the other with a preliminary counter-movement (CMJ). The calculated mechanical parameters included height of rise of center of gravity (h), average force (F), net impulse (NI) and average mechanical power (W). It was observed that the percentage of fast twitch fibers was significantly related (p< 0.05-0.01) to these variables in SJ condition and also to h and NI of the positive work phase in CMJ. It is concluded that skeletal muscle fiber composition also determines performance in a multijoint movement. The result is explainable through the differences in the mechanical characteristics of the motor units and their respective muscle fibers.
Some normal human subjects show definite synchronization of the motor units in hand muscles (i.e., the impulses from two or more motor units coincide in time more frequently than expected for independent random processes). Subjects who show synchronization tend to use their hands to exert large, brief forces, either in their work (e.g., manual laborers) or recreational activities (e.g., weightlifters). In this study all seven weightlifters examined showed a significant degree of synchronization. Furthermore, after 6 weeks of using the first dorsal interosseus muscle of the hand to exert maximal, voluntary contractions, the level of synchronization increased substantially in four control subjects, and the average level became significantly different from zero. Weightlifters also showed greater late reflex responses than control subjects, but no significant difference in earlier spinal reflexes. Two late reflex waves are described which probably involve fast pathways to and from motor cortes. We suggest that supraspinal connections from motor cortex directly to spinal motoneurons may be enhanced as a result of training to the point where they produce a significant synchronization of motor units during steady, voluntary contractions.
Article
1. Intracellular recording and stimulation techniques were used in anesthetized cats to study the interrelations between amplitudes of PSPs produced by electrical stimulation of several short-latency pathways to MG alpha motoneurons and the mechanical properties of muscle units innervated by the same cells. Motor-unit types were identified by muscle-unit properties.2. The maximum amplitudes of monosynaptic EPSPs produced in MG motoneurons by activation of homonymous (MG) and heteronymous (LGS) group Ia afferents were clearly related to motor-unit type, being, on the average, largest in type S units, somewhat smaller in type FR and F(int) units, and smallest in type FF units. Correspondingly, group Ia EPSP amplitudes were inversely correlated with muscle-unit tension production and directly correlated with resistance to fatigue. The same input distribution was true for disynaptic IPSPs produced by group Ia afferents from antagonist ankle flexors.3. The amplitudes of monosynaptic EPSPs produced by fibers descending in the ipsilateral ventral funiculi of the low thoracic cord were not clearly related to MG motor-unit type or (therefore) to muscle-unit properties.4. A quantitative input-output model of the MG motor-unit pool, based in part on the present results, suggests that overall characteristics of MG motor units, and their relative numbers in the MG pool, reflect functional specializations determined by specific mechanical demands placed on the MG muscle by the usual motor behavior of the animal.
Article
Three lines of F3 Sprague-Dawley rats derived from a single mating were raised either outside the centrifuge at earth gravity (earth control), or under chronic rotation in the center of the centrifuge at 1.03g (rotation control), or in the rim of the centrifuge at 2g (rotation experimental). The rats were killed at 3 months of age, and serial sections of plantaris and soleus muscles were stained for succinic dehydrogenase activity, and for actomyosin ATPase activity following preincubation at pH 10.2. Muscle fibers in a cross-sectional unit area of soleus and both the superficial and deep regions of plantaris were identified as to fiber type according to an enzyme profile and counted. The proportion of each fiber type was calculated, and the diameter of 24 fibers of each type was measured. Analysis of variance was used to determine the effect of experimental treatment and sex on populations and diameters. In soleus, the fiber population shifted from 82% slow oxidative fibers in the controls to 100% slow oxidative fibers in the rotation experimentals in response to the stress of hypergravity. In plantaris, chronic rotation resulted in an increase in fast glycolytic fibers and a corresponding decrease in fast oxidative glycolytic fibers, in both the rotation control and experimental rats. The population changes were similar in both sexes. Muscle fiber diameters were similar in both controls, indicating no response to the stress of chronic rotation. A sexual dichotomy was noted in response to hypergravity, with muscle fiber diameters increasing in females, but decreasing in males.
Article
The hind paws of rats were subjected to vibration at a frequency of 80 Hz., an acceleration of 32 m./s.2 rms (i.e. ah.w approximately 6.3 m./s.2 rms) for five hours daily during five consecutive days. Morphological, histochemical and immunohistochemical analyses of the soleus, extensor digitorum longus and the plantar muscles in the vibrated limb and the contralateral control limb were performed. No changes were seen in the soleus or extensor digitorum longus muscles but different degrees of degeneration of the muscle fibres were seen in the plantar muscle sections as well as signs of regeneration. No changes were observed in the contralateral unexposed limb. It is concluded that it is not only nervous tissue but also muscle tissue that can be affected by vibration. The changes seem to be confined to muscles close to the vibration exciter.
Article
In lightly alpha-chloralose anaesthetized cats, activity was recorded simultaneously from 2-4 primary muscle spindle afferents from triceps surae and/or posterior biceps and semitendinosus muscles. Increased tension in medial or lateral collateral ligament was found to evoke changes in the responses of the primary spindle afferents to sinusoidal stretching of their parent muscles. It is concluded that these changes were due to reflex actions of stretch/tension-sensitive receptors in the collateral ligaments on fusimotor neurones. Thus, receptor afferents from the collateral ligaments may contribute to the regulation of the activity in the gamma-motor-muscle-spindle system, and thereby also be of importance for the control of muscular stiffness and knee joint stability.
Article
The properties of m. soleus surface EMG recorded under conditions of voluntary contraction against vibrational stimulation were studied using vibration-triggered averaging and spectral estimates. The averaging procedure indicated EMG bursts locked to the vibration cycle. Narrow peaks appeared in the EMG spectrum at vibration frequency and harmonics. These effects were more pronounced in rectified EMG at low vibration frequencies (30-70 Hz) and in EMG at high frequencies (70-120 Hz). The disappearance of the peak after ischemic blockade preceded that of the tendon reflex. The peak normalized to the EMG power decreased when the force was enlarged. The peak augmented with prolonged contraction under vibration. The results are suggested to reflect alterations of the relative weight of the excitatory inflow through short spindle-motoneuron connections in the overall motoneuron inflow.
5 healthy males were exposed to vertical sinusoidal whole body vibration (WBV) at 5 frequencies (F1 = 0.315 Hz, F2 = 0.63 Hz, F3 = 1.25 Hz, F4 = 2.5 Hz, F5 = 5.0 Hz) and 2 intensities (I1 = 1.2 ms-2 rms, F1-F5; I2 = 2.0 ms-2 rms, F2-F5). Erector spinae EMGs were derived at the levels of the first thoracic (T1) and third lumbar (L3) spinous processes, rectified and synchronously averaged, as were the accelerations of the seat and the head. WBV induced vibration-synchronous EMG activity (T1 and L3) which exceeded the activity without WBV during enhanced gravitation and decreased during lowered gravitation from F1 to F3. At F4 and F5, these phase relations changed drastically, thus suggesting a different trigger mechanism. The extreme average EMG-amplitudes remained nearly constant at F1 to F3 and increased at higher frequencies. Maximum EMG activity was higher at I2 than at I1. WBV from F1 to F3 is supposed to cause tonic muscular activity triggered by the otoliths; at higher frequencies, stretch reflexes probably gain additional importance. The results hint at an increasing sensory conflict with decreasing frequency of WBV and are interpreted within the theoretical framework of different modes of motor control. Relations between transmissibility and muscle activity suggest the usefulness of including time-variant spring-characteristics into biomechanical models.
Article
The effect of vibrating the biceps muscle tendon on the perception of forces exerted by the elbow flexor muscles was examined during briefly maintained, submaximal contractions. Subjects were required to estimate the perceived magnitude of isometric forces exerted by the elbow flexor muscles under normal conditions and during vibration of the right biceps tendon. The matching forces produced by the unperturbed left arm provided an estimate of the perceived intensity of the reference arm contraction. Both force and the brachial biceps and triceps EMGs were recorded from each arm. In comparison with the matching forces produced under normal conditions, there was a significant overestimation of the forces exerted by the vibrated biceps muscle. This increase in the perceived intensity of the reference force was associated with an increase in the EMGs of the biceps and triceps muscles of the reference arm. It appeared that during vibration the triceps muscle was cocontracting presumably as a means of controlling the reference force. The overestimation of the forces exerted by the vibrated muscle could therefore reflect either the enhanced excitatory drive required to overcome the antagonist activity, or the concomitant increase in the force generated by the agonist muscle. Previous results suggest that the former is the more probable explanation.
Article
The mechanical behaviour of leg extensor muscles of five international-level athletes was evaluated during 13 months training period. Drop jumps, average mechanical power during 15 S continuous jump, and vertical jumps performed with and without extra weights were used to measure explosive power characteristics. The data recorded in vertical jumps was utilized for construction of force-velocity relationship (F-V curve). The athletes did not show improvement in any of the variables studied after 12 months of intensive systematic training programme. It was assumed that the subjects already had reached their upper limit of performance. However, after that the athletes underwent a simulated 3 weeks high-gravity period. The hypergravitational condition was created by wearing a special vest filled with extra loads (11% of BW). The vest was used from morning to evening. No changes in the ordinary training programme were allowed. After the simulated high-gravity conditioning period significant improvement in almost all the variables studied was observed (P less than 0.05-0.001). Vertical jump performance was enhanced from 44.3 to 54.9 cm. The F-V curve remained stable all year but after hypergravity period shifted markedly to the right. The drastic improvement was attributed to be caused by a fast adaptation to the new functional requirements (I.I g). Therefore, once the biological adaptation occurred the mechanical behaviour of the athlete's leg extensor muscle was similar to that which could be experienced in a field at low gravity condition (0.9 g). Adaptive response to the hypergravity conditioning was speculated to occur mainly at neurogenic level and less in myogenic component.
Article
Recent studies show that high frequency mechanical vibration of a human skeletal muscle tends to induce a tonic reflex contraction in this muscle and relaxation of its antagonists. This tonic vibration reflex, which probably depends upon excitation of primary spindle endings, is analyzed in the present study and technical and physiological factors determining the strength of the reflex are described. The vibrators used had a frequency range of about 20–200 cycle/sec and the amplitude could be varied stepwise from 0.5 to 3.3 mm. The EMG, force and joint movements were recorded on a multichannel inkwriter. The results show how the strength of the reflex varies with the parameters of the vibration and with the initial state of contraction and length of the muscle vibrated. A preceding muscular contraction, voluntary or induced by vibration, facilitates the reflex. Furthermore, its strength can be influenced by voluntary effort, by Jendrassik's maneuver, by general postural changes and by changes of body temperature.
Eleven international jumpers and throwers engaged in year round training were divided into experimental (n = 6) and control (n = 5) groups. The experimental group was tested before and after a 3 weeks simulated hypergravity period, and again 4 weeks after the hypergravity period. The high gravity condition was created by wearing a vest weighing about 13% of the subjects body weight. The vest was worn from morning to evening including the training sessions, and only removed during sleep. The daily training of all subjects consisted of classical weight training and jumping drills. No changes in the ordinary training program were allowed in the experimental group, except for the use of the vest. Vertical jumps, drop jumps and a 15 s continuous jumping test were used to measure the explosive power characteristics of the subjects. After the hypergravity period the experimental subjects demonstrated significant (5-10%, P less than 0.05-0.01) improvements in most of the variables studied: however, 4 weeks after cessation of the high gravity period they tended to return towards the starting values. No changes were observed in the results of the control group. The improvement observed in the experimental subjects was explained as fast adaptation to the simulated high gravity field. It is suggested that adaptation had occurred both in neuromuscular functions and in metabolic processes.
The present study was undertaken to assess the relationship between the mechanical power developed during new anaerobic power test and muscular fiber distribution. Ten track and field male athletes were used as subjects, whose muscle fiber composition (m. vastus lateralis) varied from 25 to 58 fast twitch (FT) fibers. The test consisted of measuring the flight time with a special timer during 60 s continuous jumping. A formula was derived to allow the calculation of mechanical power during a certain period of time (e.g., in the present study every 15 s during 60 s of jumping performance). The relationship between the mechanical power for the first 15 s period correlated best with fast twitch (FT) fiber distribution (r = 0.86, p less than 0.005). However, the power output during the successive 15 s periods demonstrated lower correlation with FT, and this relationship became statistically non-significant after 30 s of work. The sensitivity to fatigue of the test was supported by the relationship observed between the decrease of power during 60 s jumping performance and the percentage of FT fibers (r = 0.73, p less than 0.01). Thus, the present findings suggest that muscular performance, as determined by the new jumping test, is influenced by skeletal muscle fiber composition. The new test, which primarily evaluates maximal short term muscular power, also proved sensitive in assessing fatigue patterns during 60 s of strenuous work.
Article
In addition to the utilization of muscle's elastic energy enhancement of performance in exercise involving stretch-shortening cycle might be also due to simultaneous increase of myoelectrical activity. This hypothesis was tested by examining three athletes during jumping exercise on force-platform. Vertical jumps were performed with and without preliminary counter-movement, and the jumps were called counter-movement jump (CMJ) and squatting jump (SJ), respectively. In both conditions several jumps were performed also with extra loads on the shoulders (15–220% of b. wt.). Additional droppingjumps (DJ) were executed from different heights (20–100 cm). During jumping exercise myoelectrical activity of selected muscles from the quadriceps femoris was monitored with surface electrodes. The results obtained were similar to those reported in isolated muscle and as expected, the prestretch in CMJ shifted the force-velocity curve of concentric work to the right. In two cases enhancement of performance was attributed primarily to restitution of elastic energy because myoelectrical activity was similar to that observed in SJ. In one subject increased myoelectrical activity was observed during the concentric phase of CMJ. In DJ condition the EMG activity during eccentric phase was much higher than in SJ. Therefore the high performance in this condition was attributed to both elastic energy and reflex potentiation. In eccentric work of CMJ the average force decreased with the increase of stretching speed. This phenomenon was associated with a light increase of EMG activity. The observed results emphasize that both elastic energy and reflex potentiation may operate effectively during stretch-shortening cycle activity.
The relationships of muscle structure to the potentiation of myoelectrical activity and to the use of prestretching in five lower limb muscles were studied in different vertical jumping conditions. The subjects for the study were six male students, divided according to the muscle fiber distribution in m. vastus lateralis into "fast" and "slow" groups. The subjects performed vertical jumps (1) from a static squatting position (DJ) from five different heights. Myoelectrical (EMG) activity was recorded from mm. gluteus maximus, vastus lateralis, vastus medialis, rectus femoris and gastrocnemius in each jumping condition and integrated (IEMG) for the eccentric and concentric phases of contact. EMG activity showed potentiation during the eccentric phase of movement when compared to the concentric phase. The "fast" and "slow" groups did not differ significantly in this respect, whereas in DJ conditions the relative (% from SJ) height of rise of the center of gravity was greater in the "slow" than in the "fast" group. The result indicated that the utilization of elastic energy during jumping was possible better in subjects having a high percentage of slow twitch muscle fibres in their vastus lateralis muscles.
Article
1. Biceps femoris antagonist coactivation increases during progressive fatigue. Our purpose was to determine if the mechanism that increases coactivation during fatigue is susceptible to vibration. Vibration drives alpha-motoneurons via the Ia loop, producing force without descending motor drive, and thus uncoupling antagonist and agonist activation. Evidence that vibration increases coactivation disproportionately from its 'common drive' would suggest the possibility that some of the effects of fatigue are mediated through a segmental reflex loop. 2. Ten male subjects performed repeated maximal voluntary isometric contractions (MVCs) of the knee extensors of one leg. Paired submaximal test contractions (50% of MVC), without visual feedback, were performed when MVC reached 85, 70 and then 50% of its initial value. Vibration was applied to the patellar tendon during one test contraction in each pair. 3. Vibration reduced test contraction force below control values. However, coactivation increased at the same rate in both conditions. Biceps femoris coactivation was greater during vibration, but did not change during fatigue in either condition. 4. Our observations suggest that agonist-antagonist muscle pairs are controlled as a single motor unit pool by a common central drive. Vibrating the agonist increases antagonist coactivity, but does not alter the rate at which coactivation increases during fatigue. This supports the idea that agonist coactivation is controlled by a central mechanism.
Article
This paper describes a new method for the analysis of ensemble coding in populations of receptor afferents. The method is based on principal component analysis (PCA) combined with algorithms for calculation of stimulus separation (discrimination). It allows a quantification of the ability of ensembles of afferents to discriminate between stimuli of different intensity, and it can also be used to calculate to which extent each afferent in an ensemble contributes to the discrimination. Since the emphasis is put on discrimination of stimuli rather than on similarities between the representations of the stimulus in the ensemble response and the stimulus itself, it involves no implicit assumption about the unknown decoding mechanisms in the CNS. Examples of results obtained with analysis of and comparison of simultaneously recorded and pooled sequentially recorded populations of primary muscle spindle afferents are given. These results support some of the general arguments in favour of the ensemble coding theory, and indicate that the results of studies made on populations of simultaneously recorded receptor afferents may differ considerably from results obtained in studies on pooled sequentially recorded afferents. In contrast to when ensemble responses are based on parallel recordings, population responses constructed from sequential recordings will be distorted as a result of unavoidable temporal variations in physiological conditions.
Article
To explore possible effects of aging on the excitability of spinal reflexes. Using a cross-sectional design, the influences of muscle vibration and the Jendrassik maneuver on patellar tendon reflex function were compared between 30 young adults and 15 older adults. Motor control research laboratory. The young adults were volunteers of college age. The older adults (74.5 +/- 4.14 yr) were volunteers from the local community. All subjects were free of medications and neurological conditions that would affect normal neuromuscular responses. A force-time curve analysis of the patellar tendon reflex response was used to assess the inhibition and facilitation of spinal reflexes. In the experimental protocol to assess spinal reflex inhibition, 100 Hz vibration was applied to the right quadriceps muscle. In another experimental protocol, spinal reflex facilitation was assessed using the Jendrassik maneuver. To perform the Jendrassik maneuver, subjects were instructed to grasp their hands together and to pull as hard as possible while breathing normally. After a 2-second count, the tendon tap was delivered to the right leg and the subject was instructed to relax. In both experimental protocols, control patellar tendon reflexes were collected. Analysis of variance for reflex peak force revealed a significant 30% reduction in the amount of vibration-induced reflex inhibition with increasing age, and a similar 33% reduction in the amount of Jendrassik maneuver facilitation observed for the older adults as compared with the younger adults. These results support the hypothesis that inhibitory and excitatory influences acting on the alpha motoneuron pool are different in young and older adults.
Article
The perceived intensity of vibrotactile stimuli was studied by means of free magnitude estimation. Eighty different sinusoidal stimuli ranging in frequency from 10 to 200 Hz, and in amplitude from 2.4 to 154 microns, were presented to the left index fingerpad of psychophysical observers through a 5-mm-diameter contactor. Estimates at a given frequency increased with amplitude in all four subjects, and estimates at a given amplitude increased with frequency in three. For the fourth subject, however, intermediate frequencies (25-75 Hz) produced the most intense sensations; the relative sensory effectiveness of different frequencies suggested that in her case, perceived vibrotactile intensity was determined largely by signals in Meissner afferents. From the data of this unusual subject, and from high-frequency (200-Hz) measurements on the normal subjects, quantitative descriptions were derived of the signals in Meissner and Pacinian channels, respectively, that could contribute to subjective intensity. Candidate algorithms by which the signals from the two channels might interact were then evaluated by comparison of modeled and empirically determined subjective intensity values. It was found that subjective intensity is given by the sum of (1) the stronger of the two channels' signals, and (2) half the weaker signal, the latter apparently being reduced by cross-channel suppression that occurs only at suprathreshold levels. Adapting to 25-Hz vibration selectively reduces the perceived intensity of low frequencies, whereas adapting to 200-Hz vibration has a corresponding effect at high frequencies. It is concluded that an understanding of perceived vibrotactile intensity requires knowledge of the signals in vibrotactile channels, and of the interactions between those channels.
The influence of vibration on arm flexors mechanical power and emg activity of biceps brachii
  • C Bosco
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Bosco C, Cardinale M, Tsarpela O. The influence of vibration on arm flexors mechanical power and emg activity of biceps brachii. Eur J Appl Physiol 1999; 79:306-11.
Effect of acute whole body vibration on mechanical behavior of skeletal muscle and hormonal profile. In: Lyritis, editor. Musculo-skeletal interactions; basic and clinical aspects
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Bosco C, Colli R, Cardinale M, Tsarpela O, Bonifazi M. Effect of acute whole body vibration on mechanical behavior of skeletal muscle and hormonal profile. In: Lyritis, editor. Musculo-skeletal interactions; basic and clinical aspects. Proceedings of the 2 nd international congress. Athens: Hylonome; 1999.
Motor effects of vibratory stimuli in man
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Hagbarth KE, Eklund G. Motor effects of vibratory stimuli in man. In: R. Granit editor. Muscular afferent and motor control. Proc First Nobel Symp Stockholm: Almqvist and Wiksell; 1965.