added 2 research items
Beneficios del uso del foam roller (autoliberación miofascial) en la última parte del calentamiento | Acute foam roller (self myofascial release) benefits applied on last warm up period
Background: Injury to the anterior cruciate ligament (ACL) is common among young athletes and can impact knee stability and control. Wearing proprioceptive knee braces can improve knee control and may reduce the risk factors associated with injury and re-injury, although the effect of such braces after ACL reconstruction (ACLR) is unclear. Research question: This study aimed to determine the effect of proprioceptive knee bracing on knee control and subjective rating of participants post ACLR during three dynamic tasks. Methods: Fifteen participants 2-10 years post ACLR performed a slow step down, single leg drop jump, and pivot turn jump with and without a proprioceptive knee brace. Knee kinematics in the sagittal (flexion - extension), coronal (abduction - adduction), and transverse (internal - external rotation) planes were collected using a 3D infrared system. Paired t-tests were performed to explore differences in knee angles and angular velocities between the no brace and brace conditions during the three tasks. After each task, subjective ratings regarding ease of the task were recorded. Results: The brace reduced the peak knee external rotation angle and range of motion in the transverse plane during the pivot turn jump task, and significantly increased the maximum knee flexion angular velocity during the single leg drop jump task. The majority of participants reported that tasks were easier to perform with the proprioceptive brace than without. Significance: This study confirms that proprioceptive knee braces can significantly influence knee kinematics during dynamic tasks post ACLR. The observed effects were clinically relevant.
Objectives: This study aims to compare the effects of anterior cruciate ligament (ACL) reconstruction using autogenous hamstring or patellar tendon graft on the peak torque angle. Patients and methods: The study included 132 patients (103 males, 29 females; mean age 29±9 year) who were performed ACL reconstruction with autogenous hamstring or patellar tendon graft. The peak torque angles in the quadriceps and hamstring muscles were recorded using an isokinetic dynamometer. Results: Angle of peak knee flexion torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the hamstring tendon group. Angle of peak knee extension torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the patellar tendon group. There were no statistically significant differences in the flexion and extension peak torque angles between the operated and nonoperated knees at 60°/second in both groups. Conclusion: The angle of peak torque at relatively high angular velocities is affected after ACL reconstruction in patients with hamstring or patellar tendon grafts. The graft donor site directly influences this parameter. This finding may be important for clinicians in terms of preventing re-injury.
Objectives: Patello femoral Pain (PFP) is the most common lower limb condition encountered in clinical practice. It recently emerged as the third highest ranked topic out of 185 in the Chartered Society of Physiotherapy Musculoskeletal Research Priority Project. For a valid assessment of knee strength during rehabilitation, the isometric test using the isokinetic dynamometer (Cybex) and the hand-held dynamometer (HHD) is not well received with clinical practice. An alternative way is through functional hop tests which clinicians have used to assess their patients' lower extremity muscular strength. This study investigates the validity of knee strength assessments conducted with the HHD and the hoptest compared to the isokinetic dynamometer and also explores differences between genders of the three assessments. Design: Each assessment included one submaximal and three recorded maximal efforts of the dominant leg. Quadriceps muscle strength was displayed in normalized torques. Correlation coefficients and box-and-whisker plots was used to analyze the data. Setting: Movement analysis laboratory Participants: Sixteen males (age 23.5 ± 4.23 years, height 1.79 ± 0.08 m and body mass 76.21 ± 10.58 kg, BMI 23.82 ± 2.38 kg/m²) and 16 females (age 25.38 ± 5.49 years, height 1.67 ± 0.08 m and body mass 71.99 ± 16.05 kg, BMI 25.83 ± 4.74 kg/m²) between 18 and 40 years old without any musculoskeletal injuries participated. Main outcome measures: Knee moments normalized for bodyweight (Nm/kg) for dynamometers and distance jumped for single legged hoptest. Results: The strongest significant correlation was found for the comparison between the HHD and Cybex (r=0.71, r²=0.504, p=0.001). Correlation between the HHD and hoptest (r=0.4, r²=0.19, p=0.013), and Cybex and hoptest (r=0.53, r²=0.295, p=0.001) were poor. Comparing genders, the normalized knee extension moment on the Cybex was 28.8% lower and with the HHD 22.3% lower for females. Conclusions: Single legged hop test appears not to provide a suitable alternative for strength measurement in a clinical setting. Differences in hop performances, especially the use of the arms, seem to be important. Gender differences exist in knee strength assessments. The use of EMG-Analysis in further research might identify differences in muscle recruiting during all three tests.
Background: The Star Excursion Balance Test (SEBT) is a common clinical test that can provide information about dynamic movement, but does not reflect movement quality or postural-control strategies, and does not report kinematics of the lower limb. Purpose: To assess the dynamic postural control of healthy subjects using inertial measurement units (IMUs) and clinical SEBT scores to determine the effect of knee bracing and taping. Methods: Twenty-four healthy individuals performed the SEBT under three randomised conditions (patellar bracing, patellar taping, and control condition (no intervention). Clinical SEBT scores were recorded and normalised to leg length and angular velocities were measured using IMUs during SEBT. Composite scores were calculated as the sum of clinical scores in each direction divided by three. Descriptive statistics (mean ± sd) were calculated for each variable and repeated measures ANOVA were used to identify differences between limb (dominant, non-dominant) and condition. Main Results: Compared to the control condition, bracing and taping significantly improved dynamic postural control in the sagittal plane by 6% (1.5-10.5%) P=0.011 and 8% (2.9-13%) P=0.004 respectively. Bracing significantly improved coronal plane stability compared to the control condition by 9% (3.8-14.1%) P=0.002, and taping by 7% (1.6-12.6%) P=0.013. SEBT scores revealed small but statistically significant differences (P<0.05) between conditions in the anterior, posteromedial and composite scores, all showing a difference of between 1-2%. Principal Conclusions: Patellar soft bracing and taping can improve dynamic postural stability during SEBT. It is possible to detect clinically important changes in lower limb stability from angular velocity using IMUs.
BACKGROUND: The current gold standard of balance testing within elite academy football has been shown to be time consuming and contain movement requirements non-specific to football. PURPOSE: To assess the reliability of a new balance protocol for use in elite academy football, due to the difficulty in testing large group sizes and the limited movements patterns with the current gold standard tests. METHODS: Ten participants completed a series of functional jumps, incorporating forward, lateral and vertical movement and landing strategies, with single leg landings. The participants' jumps were videoed for retrospective analysis as well as scored in real time by two observers. The subjects balance abilities were graded based on pre-determined criteria derived from the current gold standards of balance testing. Both intra and inter-tester reliability of the functional balance protocol was assessed. MAIN RESULTS: The results show the FBP has 'excellent' inter-rater reliability for both real-time analysis and retrospective video analysis, with correlation coefficients ranging from 0.864 to 0.950. CONCLUSIONS: The FBP has excellent intra and inter-rater reliability. The research supplies evidence to suggest that using a functional protocol with an objective fail criteria combining current "gold standard" balance tests, in conjunction with minimal equipment and a short testing duration may be a more appropriate method to test balance.
BACKGROUND: There is limited research to demonstrate how scapular kinematics and shoulder-related physical characteristics are affected in water-polo players, who undertake swimming and repetitive throwing activity. The aim of this study was to investigate possible adaptations in the three- dimensional scapular kinematics and in glenohumeral internal rotation, external rotation range of motion and shoulder posterior-capsule tightness in water-polo players. METHODS: Fourteen water-polo players and 14 asymptomatic volunteers participated in the study. The scapular kinematics were recorded using an electromagnetic tracking device during the scapular plane shoulder elevation. Additionally, shoulder range of motion and posterior-capsule tightness were evaluated. Analysis of variance models were used to make comparisons between groups. RESULTS: Although there was a trend toward increased scapular internal rotation and downward rotation in the throwing shoulders of water-polo players, comparisons revealed there was no significant differences in kinematics, shoulder internal-external range of motion and posterior-capsule tightness between the throwing shoulders of the players and dominant shoulders of the control participants. CONCLUSIONS: The throwing shoulders of water-polo players did not demonstrate alterations in shoulder kinematics and mobility parameters.
The aim of the current investigation was to determine whether there are gender differences in triceps surae muscle kinematics during a 45° cut movement. Fifteen male and fifteen female recreational athletes performed 45° cut movements using an approach velocity of 4.0 m.s-1. Kinematics were measured using an eight camera motion analysis system. Muscle kinematics from the lateral gastrocnemius, medial gastrocnemius and soleus were obtained using musculoskeletal modelling software (Opensim v3.2). The results showed that muscle strain at the lateral Gastrocnemius (male = 2.26 and female = 1.15%), medial Gastrocnemius (male = 2.27 and female = 1.08%) were significantly (p< 0.05) larger in male athletes. Given the proposed association between the extent of muscle strain and the aetiology of chronic muscle strain pathologies, the current investigation indicates that male athletes may be more susceptible to triceps surae strain injuries when performing the 45° cut movement.
BACKGROUND:Individuals who suffer from ankle instability may experience restricted movement and a weakening of the muscles that support the ankle. PURPOSE:The aim of this study was to investigate the effects of functional instability of the ankle joint on static and dynamic balance performances. METHODS:Twenty-five participants (8 male, 17 female) were recruited for this study. The subjects were divided into two groups: an ankle instability and a normal ankle stability group. The static and dynamic limits of stability performance were assessed in single leg standing using the BioRescue device. In addition, the Functional Reach Test (FRT) and the Modified Functional Reach Test (MFRT) were also recorded. RESULTS:Significant differences between the two groups were found in the moving distance and the mean velocity of the center of pressure during the single leg standing test, the pendular limits of stability test, and the MFRT. However, the FRT showed no significant difference between the two groups. The results showed that the static and dynamic balance performances were reduced in the ankle instability group compared with the control group. CONCLUSION:Both the MFRT and BioRescue were sensitive and appropriate to identify clinically important differences between the two groups. The MFRT is a quick and inexpensive clinical measure of postural instability relevant to individuals with ankle instability. Further studies should use the MFRT to determine the effectiveness of clinical interventions for ankle instability that target improvements in balance.
Minimalist footwear has been the subject of much attention in footwear research. More recently, maximalist footwear, which feature an oversized midsole have been developed. The aim of the current investigation was to compare the kinetics and kinematics of running in minimalist, maximalist and conventional footwear. Twelve male runners ran over an embedded force platform at 4.0 m s−1 in the three footwear conditions. Lower limb kinematics were collected using an eight-camera motion capture system, and tibial accelerations were obtained using an accelerometer. Differences in kinetics and kinematics between footwear were examined using one-way repeated measures ANOVA. The results showed that both instantaneous loading rate and peak tibial acceleration were significantly larger in the minimalist (305.58 BW/s and 9.54 g) compared to the maximalist (141.67 BW/s and 7.99 g) and conventional (127.30 BW/s and 6.73 g) footwear. In addition, peak tibial internal rotation was significantly larger in the minimalist (9.64°) compared to conventional (6.88°) footwear. These findings indicate that minimalist footwear may place runners at increased risk from chronic injury. Further work is, nonetheless, required using runners who habitually utilize these footwear before these findings can be truly substantiated.
INTRODUCTION Over the last decade, the use of Kinesiology-Type Tape (KTT) has become increasingly popular in sports for injury prevention, injury management and performance enhancement. Many cyclists use patella KTT; however, the benefits of such interventions remain unclear, especially in uninjured elite cyclists. We aimed to determine the acute physiological, kinematic and electromyographic (EMG) responses to applying patella KTT in elite cyclists. METHODS Twelve elite male cyclists with no current or recent (< 1 month) injury completed the experimental protocol. All cyclists had at least four years of training experience and competed nationally. Cyclists performed 4-min submaximal cycling trials at 100 and 200 W on a Lode ergometer set-up to mimic their individual road cycling positions. Trials were carried out in a randomized order with and without patella KTT separated by 5-min passive recovery. Physiological measurements were monitored using the K5 wearable metabolic technology wireless system (COSMED, Rome, Italy) and Polar® heart rate monitor (Polar Electro, Kempele, Finland). Cycling economy, energy cost, oxygen cost, and heart rate measures were taken over the last minute when steady state was assumed. Kinematics and EMG signals were also collected over the last minute using an infrared camera system (Qualisys AB, Gothenburg, Sweden) and wireless EMG sensors (Noraxon USA Inc., Scottsdale, AZ). Following all trials, each cyclist rated their perceived comfort levels and change in knee stability and cycling performance with KTT. RESULTS AND DISCUSSION Patella KTT had non-significant trivial effects on all collected physiological parameters. The effects of KTT on range of motion values of the ankle, knee, hip, pelvis, and trunk were non-significant and mostly trivial; except for a subset of small non-significant effects observed at the ankle and knee at 100 W, and at the knee, pelvis and trunk at 200 W (see Table 1). Patella KTT significantly and meaningfully increased peak, mean, and integrated EMG signals from vastus medialis, and altered the vastus medialis to vastus lateralis activation ratio. Peak, mean, and integrated EMG signals from biceps femoris and rectus femoris also generally decreased; with changes indicating an increased biceps femoris to rectus femoris ratio. Changes in EMG signals with patella KTT were more pronounced at the lower power. Most cyclists perceived KTT as comfortable (n = 7, 58%), providing additional knee stability (n = 10, 83%), and improving cycling performance (n = 11, 92%). Perceptions were not always well matched with individual responses. CONCLUSIONS Despite most cyclists perceiving an increased performance and knee stability with patella KTT; the intervention had no significant or meaningful impact on the physiological parameters and knee kinematic measures investigated. However, patella KTT did appear to stabilize the proximal segments and impact EMG signals, notably decreasing pelvis and trunk range of motion, increasing vastus medialis signals and recruitment in relation to vastus lateralis, and increasing biceps femoris recruitment in relation to rectus femoris. Hence, KTT has the potential to alter the neuromuscular recruitment patterns of elite cyclists, which could have implications for injury prevention, especially the development of patella femoral pain. The persistence of the neuromuscular changes seen has not yet been established, and the ability of patella KTT to directly enhance elite cycling performance is most likely trivial. The range of responses to KTT seen here implies the presence of positive responders, negative responders, and non-responders; however, perceptions were not able to clearly delineate cyclists into these subgroups.
Introduction It has been estimated that up to 70% of runners will sustain an overuse injury during any one year period (Caspersen et al, 1984). Repetitive and abnormal loading of the lower limb with high loading rates has been shown to increase the occurrence of overuse injuries, such as tibial stress fractures (Milner et al, 2006). Therefore much emphasis has been placed upon achieving optimum shock absorption through specially designed running shoes. The introduction of springs in footwear is not a new idea, however the recent development of micro-spring technology now allows a higher density spring configuration. This study explored the effectiveness of high density micro-springs in reducing impact forces and vertical loading rates during running. Methods Three-dimensional kinematics and kinetics were recorded from 11 healthy recreational heel striker runners during overground running in a Movement Analysis Laboratory. Two versions of a branded running shoe were tested; one pair remained unmodified and the other was modified with 30 high density micro-springs. Test conditions were blinded and randomised. Each subject completed 5 running trials of approximately 20 m under each test condition at a self-selected speed. A paired t-test was conducted to determine the changes in biomechanics between the two conditions. Results No significant differences were seen in the peak vertical ground reaction force, the anterior push off force or the contact time. However, the introduction of the high density micro-springs showed a significant reduction in the vertical loading rate of 7.3 body weights per second or 10.4% (p=0.02) compared with the unmodified shoe and a significant reduction of 0.048 N/BW or 18% in the peak posterior ground reaction force at impact (p=0.012). Discussion The similarity in the contact time and the peak vertical loading force indicate similar propulsion performance. However the reduction in the vertical loading rate and posterior ground reaction forces acting with the high density micro-springs may make clinically important differences which could help runners who report overuse running injuries. The balance between the spring stiffness and surrounding damper materials of the sole is worthy of further exploration for different sports and recreational footwear. References Caspersen CJ, Powell KE, Koplan JP, Shirley RW, Campbell C, Sikes RK. (1984). The incidence of injuries and hazards in recreational and fitness runners. Medicine and Science in Sport and Exercise 16, pp.113–114 Milner, C.E., Ferber, R., Pollard, C.D., Hamill, J. & Davis, I.S. (2006) Biomechanical factors associated with tibial stress fracture in female runners. Medicine and science in sports and exercise, 38 (2), pp.323–8.
Background: The objectives of this study were to investigate the effects of knee brace (KB) and kinesiotaping (KT) on functional performance and self-reported function in individuals six months post-ACLR who desired to return to their pre-injury activity levels but felt unable to do so due to kinesiophobia. Methods: This was a cross-sectional study involving 30 individuals six months post-ACLR with Tampa Kinesiophobia Scores >37. Individuals were tested under three conditions: no intervention, KB and KT in a randomized order. Isokinetic concentric quadriceps and hamstring strength tests, one leg hop test, star excursion balance test and global rating scale were assessed under the three conditions. Results: The involved side showed that KT and KB significantly increased the hop distance (P=0.01, P=0.04) and improved balance (P=0.01, P=0.04), respectively, but only KB was found to increase the quadriceps and hamstring peak torques compared to no intervention (P<0.05). Individuals reported having better knee function with KB when compared to no intervention (P<0.001) and KT (P=0.03). Conclusions: Both KB and KT have positive effects in individuals post-ACLR which may assist in reducing kinesiophobia when returning to their pre-injury activity levels, with the KB appearing to offer the participants better knee function compared to KT.
Soccer matches consist of a variety of different activities, including repeated sprints. Time to attain velocity (TTAV), load range (LR) and the torque-angle-velocity relationship (TAV3D) represent an important measurement of muscle performance, however there are few related studies. The aim of this study was to compare these outcomes between soccer players of different age category. 17 professional (PRO) and 17 under-17 (U17) soccer players were assessed for concentric knee flexion/extension at 60, 120 and 300°/s. For the extensor muscles, differences were found in favor of the U17 group for TTAV and LR outcomes at 120°/s, however, the PRO group maintained higher torques in both movement directions in comparison to the U17 in TAV3D evaluation. These results suggest that muscle performance of the PRO group is more efficient than the U17 group. © Georg Thieme Verlag KG Stuttgart · New York.