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Mechanical jumping power in athletes
Abstract
The Wingate cycle ergometer test is a widely used test of sustained muscular power. A limitation of the test is the lack of development and retrieval of stored elastic energy due to a lack of an eccentric phase. To measure mechanical power output of the entire stretch-shortening cycle, the test of Bosco et al (1983) was administered to 119 male athletes in 7 different activities during their pre-participation evaluations. The sports tested were indoor soccer, American football and ballet (professionals), outdoor soccer, basketball and wrestling (collegiate) and amateur bobsled. Results showed the overall average power output to be 20.37 W.kg-1 for the 60s reciprocal jumping test. Ballet dancers generated significantly less mechanical power than indoor soccer, basketball and bobsled athletes, while wrestlers generated significantly less power than indoor soccer and basketball athletes (all p less than 0.05). No other between-sport differences were seen. A subset of indoor soccer players (n = 10) were retested after 4 months of training. Power improved from 20.8 to 24.3 W.kg-1 (p less than 0.05). While between sport differences were limited, training differences in one subset of athletes were readily identified.
... force (~22-24 N·kg -1 ) during a countermovement jump 160,241 and mean power during a Bosco repeated jump test (18 W·kg-1) 235 were reported in professional ballet dancers. Perry et al. 242 reported peak vertical ground reaction force (vGRF), mean rate of force development (RFD), peak ankle joint moment, and peak power during takeoff of a horizontal and vertical unilateral ballet-specific jump, demonstrating higher values during the horizontal take-off (Cohen's d >0.80). ...
... Professional ballet dancers have demonstrated lower mean power than both amateur and professional athletes during a Bosco repeated jump test. 235 When ballet dancers have been compared to volleyball athletes, ballet dancers have demonstrated larger ankle moments, power, and work, although no statistical analysis was conducted. 109 Critical appraisal scores ranged from 10-16 (Table 4.4). ...
... Twenty-one studies investigated ballet-specific jumps,234,[236][237][238][239][240][242][243][244][245][246][247][248][249][250][251][252][253]255,257,258 six investigated non-specific jumps,105,160,235,241,254,256 and two investigated both balletspecific and non-specific jumps.80,109 Appendix A provides a glossary of included ballet-specific jumps. ...
Jumping and landing activities are the most common mechanism of injury in professional ballet dancers. There is limited evidence, however, that has elucidated the moderators of load experienced when jumping and landing in ballet. This thesis aimed to describe injury epidemiology, establish reliable methods of assessing strength and jumping, and explore the factors that may influence lower extremity load during jump landings in professional ballet dancers.
A five-year injury epidemiology study revealed an incidence of medical attention and time-loss injuries of ~3–4 and ~1 per 1000 h of exposure, respectively. The mechanism of injury was jumping and landing activities in ~30–40% of time loss injuries. A systematic review found limited evidence that ballet dancers demonstrate externally rotated lower extremities, extended lower extremities prior to landing, and ankle-dominant jumping strategies.
Two methodological studies established the within- and between-session reliability of vertical ground reaction force (vGRF) across several maximal isometric force tests and three-dimensional ankle mechanics during landing in turnout and parallel foot positions. The reliability of vGRF during maximal isometric force tests across the squat, standing plantarflexion, and seated plantarflexion positions demonstrated excellent reliability (intraclass correlation coefficients (ICC): 0.92–1.00) and low variability (coefficient of variation (CV): 2.0–6.5%). Three-dimensional ankle mechanics demonstrated within- (ICC: 0.17–0.96; CV: 1.4¬–82.3%) and between-session (ICC: 0.02–0.98; CV:1.3–57.1%) reliability ranging from poor to excellent, with, ankle excursion, peak ankle angle, and jump height demonstrating the greatest ICC values (ICC: 0.65–0.96; CV: 1.4–57%).
The final two studies investigated jump landings in professional ballet dancers. A linear discriminate analysis revealed that three-dimensional ankle mechanics could discriminate different ballet foot positions, such that jump landings in fourth and fifth positions required a greater range of motion and ankle joint power when compared to other foot positions. Lastly, two linear mixed-effects models indicated that peak ankle joint moments and vGRFs have poor associations with strength, ankle dorsiflexion range of motion, and three-dimensional ankle excursions (R2: 0.01–0.02). Sex, foot position, and individual variation are more appropriate factors to consider when assessing the load experienced at a joint or system level.
This thesis provides a thorough insight into injury, strength, and jumping in professional ballet dancers. To that end, this thesis has identified burdensome injuries and their mechanisms in professional ballet dancers alongside practical and reliable strategies to measure the physical attributes that may moderate the load experienced by a dancer upon landing.
... A detailed overview of the results of the included studies is presented in Table 1. Twenty-one studies investigated ballet-specific jumps, (32,34,(37)(38)(39)41,(43)(44)(45)47,(49)(50)(51)(52)(53)(55)(56)(57)(58)(59)(60) 6 investi-gated non-specific jumps, (33,36,40,42,46,48) and 2 investigated both ballet-specific and non-specific jumps. (35,54) Appendix 1 provides a glossary of included ballet-specific jumps. ...
... (35,54) Appendix 1 provides a glossary of included ballet-specific jumps. Nineteen studies exclusively investigated female ballet dancers, (33,36,39,41,43,44,46,(48)(49)(50)(52)(53)(54)(55)(56)(57)(58)(59)(60) 2 investigated males, (40,45) 2 investigated males and females, (38,47) and 6 did not specify the sex of participants. (32,34,35,37,42,51) Fourteen studies investigated adults, (35,(39)(40)(41)(42)(43)(44)47,49,50,54,55,57,59) 10 investigated adolescents, (33,(36)(37)(38)46,48,53,56,58,60) 1 investigated a mix of adults and adolescents, (32) and 3 did not specify the age of participants. ...
... Nineteen studies exclusively investigated female ballet dancers, (33,36,39,41,43,44,46,(48)(49)(50)(52)(53)(54)(55)(56)(57)(58)(59)(60) 2 investigated males, (40,45) 2 investigated males and females, (38,47) and 6 did not specify the sex of participants. (32,34,35,37,42,51) Fourteen studies investigated adults, (35,(39)(40)(41)(42)(43)(44)47,49,50,54,55,57,59) 10 investigated adolescents, (33,(36)(37)(38)46,48,53,56,58,60) 1 investigated a mix of adults and adolescents, (32) and 3 did not specify the age of participants. (34,45,51) Nine studies investigated professional ballet dancers, (35,40,43,45,46,48,50,51,54) 18 investigated non-professionals, (32)(33)(34)(36)(37)(38)(39)41,42,44,49,52,(55)(56)(57)(58)(59)(60) and 2 investigated a mix of professionals and non-professionals. ...
Aims:
Understanding the biomechanics of jumping in ballet dancers provides an opportunity to optimize performance and mitigate injury risk. This systematic review aimed to summarize research investigating kinetics and kinematics of jumping in ballet dancers.
Methods:
PubMed (MEDLINE), SPORTDiscus, and Web of Science were systematically searched for studies published before December 2020. Studies were required to investigate dancers specializing in ballet, assess kinetics or kinematics during take-off or landing, and be published in English.
Results:
A total of 3,781 articles were identified, of which 29 met the inclusion criteria. Seven studies investigated take-off (kinetics: n = 6; kinematics: n = 4) and 23 studies investigated landing (kinetics: n = 19; kinematics: n = 12). Included articles were categorized into six themes: Activity Type (n = 10), Environment and Equipment (n = 10), Demographics (n = 8), Physical Characteristics (n = 3), Injury Status (n = 2), and Skill Acquisition and Motor Control (n = 1). Peak landing vertical ground reaction force (1.4-9.6 times body weight) was most commonly reported. Limited evidence suggests greater ankle involvement during the take-off of ballet jumps compared to countermovement jumps. There is also limited evidence indicating greater sagittal plane joint excursions upon landing in ballet dancers compared to non-dancers, primarily through a more extended lower extremity at initial contact. Only 4 articles investigated male ballet dancers, which is a notable gap in the literature.
Conclusions:
The findings of this review can be used by dance science and medicine practitioners to improve their understanding of jumping in ballet dancers.
... The power output scores produced in this study tended ta be lower than those cited in other studies which used the Bosco Jumping test protocol.Table 17 displays the power scores (Wjkg) from the present study, and studies using the Bosco Jump test (Bosco et al., 1983b: Kirkendall and street, 1986: viitasalo et al., 1987: Bosco et al., 1986). In this study, the mean power scores were 20.4 W/kg over 15 sand 15.4 W/kg over 60 s. ...
... In a study by Kirkendall and Street (1986) power output was measured with the Bosco et al. (1983b) protocol. The subjects were 9articipants in six athletic teams and ballet dancers (n = 119). ...
... The subjects were 9articipants in six athletic teams and ballet dancers (n = 119). The calculated power output (W/kg), from each of the seven groups in Kirkendall and Street's (1986) study were higher than the power output scores obtained by subjects in the present study. t There may be three explanations for the discrepancies found between the power output cited in other studies and the power output from the present study. ...
... Dancers train using only bodyweight, the load at which power output during jumping is maximised (Cormie et al., 2007); thus it is intuitive that as power athletes, dancers' SSC capability would be strongly influenced by maximal isometric strength . The stereotype that dancers are weaker and less powerful than most team sport athletes has been possibly confounded by (1) isometric strength testing at joint angles infrequently employed (Rice et al., 2017), (2) field testing that doesn't mimic dance-specific movements (Kirkendall & Street, 1986) and (3) the portrayal of effortlessness during movements that are not only technically complex, but also require significant strength. However, limited research exists on biomechanical determinants of dancers' SSC performance and dance-specific SSC performance. ...
... Relative peak power was the strongest predictor of weighted parameter ranking saut de chat performance, PCA ranking and leap height (Tables 3 and Table 5), as hypothesised. Contrary to some research that indicates dancers transfer less power than other athletes during repeated SSC tasks (Kirkendall & Street, 1986), these findings postulate that during a single dance-specific SSC, power is the best predictor of overall leaping performance. The established association between leaping performance and system power suggests that dancers may benefit from some combination of plyometric and power training to further progress SSC capabilities (Rice & Nimphius, 2020), as has previously been employed (Brown et al., 2007). ...
Limited research exists on the relationship between aesthetic saut de chat performance and muscle-tendon unit (MTU) characteristics of dancers. We developed a weighted parameter ranking (WPR) tool to incorporate aesthetic leaping aspects (i.e., height, peak split angle, average trunk angle and trunk angle range) for correlation with MTU properties. The purpose was to identify the relationship of saut de chat WPR and leap height with maximal plantarflexion strength, medial gastrocnemius (MG) stiffness, Achilles tendon (AT) stiffness and relative peak power (PP). Dancers (n = 18) performed maximal plantarflexion, short-range stretches and isometric ramping contractions on a dynamometer equipped with ultrasound to determine strength, MG stiffness and AT stiffness, respectively. Subjects then performed saut de chat leaps atop force platforms surrounded by motion capture cameras. A principal component analysis (PCA) was performed to compare WPR variable weightings with PCA results and rankings. Moderate–strong relationships were identified among WPR, maximal plantarflexion strength, MG stiffness and PP. Strong–very strong relationships were also identified between leap height and maximal plantarflexion strength, MG stiffness, AT stiffness, peak split angle and PP. A very strong correlation existed between PCA rankings and WPRs. Practitioners may consider developing strength and power capabilities in dancers to improve leaping.
... The Mean Power was estimated by the amount of work during a 60-second continuous effort. For PP and MP, the results were expressed in watts/kg (W/kg), according to the equation described by Bosco et al. (1983) (Bosco et al., 1983, Kirkendall et al., 1986, Kums et al., 2005, Jefferson et al., 2006, 2007. The fatigue index (FI) was calculated as the difference between the power peak (work produced in the first 15 seconds) and the mean power generated in the last 15 seconds of a continuous vertical jump work of 60 seconds relative to first 15 seconds peak power. ...
... The result was expressed in percentage (%) (Jefferson et al., 2006, 2007, Kums et al., 2005. The following formulas were used to calculate various biomechanical variables related to jump tests: 1. Peak Power or Mean Power (W) = (Ft×Ts×g2) / 4n (Ts -Ft) (Bosco et al., 1983, Kirkendall et al., 1986, Kums et al., 2005, Jefferson et al., 2006, 2007 The average power generated (W) is calculated from the test duration (Ts) from 0 to 60 second, the number of jumps (n), total flight time (Ft) and where g is the acceleration due to gravity. The unit of mechanical power per mass unit is Watts per kg (W/kg). ...
... The mean relative power scores of the athletes in the present study tented to be developed more than other college wrestlers in one study in which wrestlers generated significantly less power than indoor soccer and basketball athletes (D. Kirkendall, 1986). In wrestlers, publications measuring anaerobic capacity with Bosco test are rare. Besides, comparing the results of the Bosco test with other anaerobic tests is difficult despite the high positive correlation between them (Viitasalo, L, Alen, P, & E, 1987;William et al., 2004). The power output generated in the Bosco test is higher tha ...
... m cracking and 7,4 to 9,4 for Wingate tests in the same study (Horswill, 1992). But in studies with subjects from different athletic teams showed varied average power outputs in Bosco test which is between 18,79 to 26,6 W/kg for volleyball, basketball, handball, footballers. (Carmelo Bosco et al., 1983;Hespanhol, Gonçalves, Neto, & De Arruda, 2006;D. Kirkendall, 1986;Viitasalo et al., 1987). Bosco test's average power values of volleyball players and basketball players is higher than the other athletes in these studies may be explained as the jumping ability and using elastic energy kinetics is more developed in these athletes (Carmelo Bosco et al., 1983). As a result, in six months of qualification ...
This study aimed to evaluate the national level wrestlers’ anaerobic capacity through the preparation and qualification periods for Rio 2016 summer Olympic Games. For this manner, 10 national level freestyle wrestlers’(age 22,10 ± 3,21; weight 64,75 ±6,34; height 164,31 ± 4,75) anaerobic outputs measured 3 times in three month intervals with Bosco repeated jump test. Peak Jump(cm), Flight time, average power, average power/weight, first 15sec average jump height, last 15sec average jump height, fatigue index scores analyzed with repeated measures Anova. Mean power/weight output of the wrestlers increased from 20,42 W/kg to 21,28 W/kg(4,21 %) and fatigue index is decreased from 1,185 to 1,142 (3,62 %). However, this increase was not statistically significant (p<0,05). In six months of qualification and preparation period wrestlers’ anaerobic capacity did not changed and it is thought to have been caused by some reasons such as having already reached a certain anaerobic peak level or athletes’ competition level and frequency which might made it difficult for them to have a proper periodization during the year.
... Such type of explosive plyometric exercises is used by the power athletes because it utilizes the rapid concentric contraction and eccentric elongation which occurred by the activation of stretch-shortening cycle [7][8][9]. Recent studies suggest that the timing of hamstring muscle activation and the amplitude of gluteal and abdominal muscle activation are important in order to prevent hamstring injuries. ...
BACKGROUND: Basketball is a high intensity contact sports with complex movements that includes jumps, turns
... Tot i no seguir estrictament els criteris del test de Conconi, s'accepta que complint certs criteris qualsevol prova pot enregistrar valors de FC adequats per al seu estudi (Conconi i al. , 1996). antropomètric (Ackland, Schreiner i Kerr, 1997;Bale, 1991;Bayios i al. , 2006;Drinkwater i al. , 2008;Greene i al. , 1998;Jelicic i al. , 2002;McKenzie, 1985;Toriola, Adeniran i Ogunremi, 1987;Toriola, Salokun i Mathur, 1985;Ugarkovic i al. , 2002;Viviani, 1994;Young i al. , 2005), de la capacitat de salt (Apostolidis i al. , 2004;Bale, 1991;Greene i al. , 1998;Hakkinen, 1993;Kirkendall i Street, 1986;LaMonte, McKinney, Quinn, Bainbridge i Eisenman, 1999;Ostojic i al. , 2006;Rivera i Suarez, 1990;Ugarkovic i al. , 2002;Woolstenhulme, Bailey i Allsen, 2004;Young i al. , 2005) o de suportar esforços (Bale, 1991;Ben Abdelkrim i al. , 2007;Castagna, Impellizzeri i al. , 2008;Crisafulli i al. , 2002;Ghosh, Ahuja i Khanna, 1987;Gocentas i Andziulis, 2004;Ostojic i al. , 2006;Sallet i al. , 2005;Vaquera, 2003), han contribuït, poc a poc, a descriure una imatge de les habilitats que ha de posseir un jugador de basquetbol per a la pràctica d'alt nivell. Aquest conjunt de coneixement ens ha d'ajudar a l'hora de seleccionar objectius i medis d'entrenament per assolir els nivells de rendiment desitjats. ...
Basketball is an intermittent sport with variable efforts and recovery periods. The aim of the present research is to provide insight about the game requirements and players’ characteristics, and is divided into six sections: 1) analysis of the game requirements in simulated game situation (game test); 2) description of the maximal aerobic power (VO2max) by using an incremental test (20 meters shuttle-run test); 3) comparative study of the in-game requirements and maximal test requirements; 4) determination of the relationship between the HRdP (heart rate deflection point), ventilatory thresholds (VT1 i VT2) and VO2max; 5) assessment of the predictive ability of both tests to obtain an estimation of the VO2game with the HR (heart rate) and 6) assessment of the predictive power of both tests to obtain an in-game estimation of the energy expenditure using the HR. Thirty basketball players, belonging to Catalan basketball organizations, participated in the study. The subjects were divided into ‘national team’ and ‘non-national team’ groups according to his performance level and into ‘guards’, ‘forwards’ and ‘centers’ in agreement with their playing role. The results showed that when using the simulated game test, players reached a high VO2game near to their VO2max, with peaks of maximum demands. We provided calculations to obtain the game load by using the TRIMPs methodology. The game test has proven to be valid to estimate VO2 values during game situations based on the HR–VO2 individual regression and the HR recordings performed during the actual game. Junior basketball players showed a high level of aerobic performance despite their intermediate level of aerobic power (VO2max). The 20 meters shuttle-run test showed a moderate predictive ability of VO2game. The study of the oxygen uptake kinetics provided knowledge of two key factors in intermittent activities: on and off-transient kinetics. The HRdP stood between the VT2 and the VO2max. Between tests comparison revealed that, despite some specific peaks that may at some point reach 100% of VO2max, game test is not maximal at all while 20 meters shuttle-run test really is. National team players performed better and showed better VO2max levels and higher energy expenditure profile in both tests. Based on the playing role, guards showed better aerobic power, more than probably due to the higher demands of this position during the game. For this reason worse performance was showed by centers whereas, forwards were the role with the better aerobic performance profile (VT1 and VT2 near VO2max).
... Impellizzeri, F., Rampinini, E., Castagna, C., Martino, F., Fiorini, S, & Wislo21. Nakada, M., Demura, S., Yamaji, S., Nagasawa, Y., 1986;Malisoux, et al., 2006) y de la salud (Caserotti, et al., 2008). De esa forma, diferentes métodos de evaluación de la potencia mecánica ha sido propuestas en la literatura específica, con el objetivo de validarlos (Margaria et al., 1999;Fox, Mathews, 1994;Bosco, 1983a;Harman, et al., 2001;Sayers, et al., 1999)principalmente del metabolismo aneróbico lactácido (Nunes, et al., 2010)., et al., 2002;Fatouros, et al., 2010;Tatavulj et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995Este método es ampliamente usado en las sesiones de entrenamiento (Adams, et al., 2002;Fatouros, et al., 2010;Tatavulj, et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995) y consecuentemente, en las acciones deportivas. ...
... Impellizzeri, F., Rampinini, E., Castagna, C., Martino, F., Fiorini, S, & Wislo21. Nakada, M., Demura, S., Yamaji, S., Nagasawa, Y., 1986;Malisoux, et al., 2006) y de la salud (Caserotti, et al., 2008). De esa forma, diferentes métodos de evaluación de la potencia mecánica ha sido propuestas en la literatura específica, con el objetivo de validarlos (Margaria et al., 1999;Fox, Mathews, 1994;Bosco, 1983a;Harman, et al., 2001;Sayers, et al., 1999)principalmente del metabolismo aneróbico lactácido (Nunes, et al., 2010)., et al., 2002;Fatouros, et al., 2010;Tatavulj et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995Este método es ampliamente usado en las sesiones de entrenamiento (Adams, et al., 2002;Fatouros, et al., 2010;Tatavulj, et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995) y consecuentemente, en las acciones deportivas. ...
... Impellizzeri, F., Rampinini, E., Castagna, C., Martino, F., Fiorini, S, & Wislo21. Nakada, M., Demura, S., Yamaji, S., Nagasawa, Y., 1986;Malisoux, et al., 2006) y de la salud (Caserotti, et al., 2008). De esa forma, diferentes métodos de evaluación de la potencia mecánica ha sido propuestas en la literatura específica, con el objetivo de validarlos (Margaria et al., 1999;Fox, Mathews, 1994;Bosco, 1983a;Harman, et al., 2001;Sayers, et al., 1999)principalmente del metabolismo aneróbico lactácido (Nunes, et al., 2010)., et al., 2002;Fatouros, et al., 2010;Tatavulj et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995Este método es ampliamente usado en las sesiones de entrenamiento (Adams, et al., 2002;Fatouros, et al., 2010;Tatavulj, et al., 2001) y ha sido demostrado ser un método efi ciente para mejorar la altura alcanzada en el salto vertical (Kraemer, et al., 1995) y consecuentemente, en las acciones deportivas. ...
... Tot i no seguir estrictament els criteris del test de Conconi, s'accepta que complint certs criteris qualsevol prova pot enregistrar valors de FC adequats per al seu estudi (Conconi i al. , 1996). antropomètric (Ackland, Schreiner i Kerr, 1997;Bale, 1991;Bayios i al. , 2006;Drinkwater i al. , 2008;Greene i al. , 1998;Jelicic i al. , 2002;McKenzie, 1985;Toriola, Adeniran i Ogunremi, 1987;Toriola, Salokun i Mathur, 1985;Ugarkovic i al. , 2002;Viviani, 1994;Young i al. , 2005), de la capacitat de salt (Apostolidis i al. , 2004;Bale, 1991;Greene i al. , 1998;Hakkinen, 1993;Kirkendall i Street, 1986;LaMonte, McKinney, Quinn, Bainbridge i Eisenman, 1999;Ostojic i al. , 2006;Rivera i Suarez, 1990;Ugarkovic i al. , 2002;Woolstenhulme, Bailey i Allsen, 2004;Young i al. , 2005) o de suportar esforços (Bale, 1991;Ben Abdelkrim i al. , 2007;Castagna, Impellizzeri i al. , 2008;Crisafulli i al. , 2002;Ghosh, Ahuja i Khanna, 1987;Gocentas i Andziulis, 2004;Ostojic i al. , 2006;Sallet i al. , 2005;Vaquera, 2003), han contribuït, poc a poc, a descriure una imatge de les habilitats que ha de posseir un jugador de basquetbol per a la pràctica d'alt nivell. Aquest conjunt de coneixement ens ha d'ajudar a l'hora de seleccionar objectius i medis d'entrenament per assolir els nivells de rendiment desitjats. ...
Basketball is an intermittent sport with variable efforts and recovery periods. The aim of the present research is to provide insight about the game requirements and players’ characteristics, and is divided into six sections: 1) analysis of the game requirements in simulated game situation (game test); 2) description of the maximal aerobic power (VO2max) by using an incremental test (20 meters shuttle-run test); 3) comparative study of the in-game requirements and maximal test requirements; 4) determination of the relationship between the HRdP (heart rate deflection point), ventilatory thresholds (VT1 i VT2) and VO2max; 5) assessment of the predictive ability of both tests to obtain an estimation of the VO2game with the HR (heart rate) and 6) assessment of the predictive power of both tests to obtain an in-game estimation of the energy expenditure using the HR. Thirty basketball players, belonging to Catalan basketball organizations, participated in the study. The subjects were divided into ‘national team’ and ‘non-national team’ groups according to his performance level and into ‘guards’, ‘forwards’ and ‘centers’ in agreement with their playing role. The results showed that when using the simulated game test, players reached a high VO2game near to their VO2max, with peaks of maximum demands. We provided calculations to obtain the game load by using the TRIMPs methodology. The game test has proven to be valid to estimate VO2 values during game situations based on the HR–VO2 individual regression and the HR recordings performed during the actual game. Junior basketball players showed a high level of aerobic performance despite their intermediate level of aerobic power (VO2max). The 20 meters shuttle-run test showed a moderate predictive ability of VO2game. The study of the oxygen uptake kinetics provided knowledge of two key factors in intermittent activities: on and off-transient kinetics. The HRdP stood between the VT2 and the VO2max. Between tests comparison revealed that, despite some specific peaks that may at some point reach 100% of VO2max, game test is not maximal at all while 20 meters shuttle-run test really is. National team players performed better and showed better VO2max levels and higher energy expenditure profile in both tests. Based on the playing role, guards showed better aerobic power, more than probably due to the higher demands of this position during the game. For this reason worse performance was showed by centers whereas, forwards were the role with the better aerobic performance profile (VT1 and VT2 near VO2max).
... A potência mecânica é caracterizada como a quantidade de trabalho por unidade de tempo, ou como a variação de energia mecânica produzida por unidade de tempo (CHELLY;DENIS, 2001;KYRÖLÄINEN et al., 2004;MARKOVIC;JARIC, 2007). Essa capacidade permite ao sistema neuromuscular dominar resistências com a maior velocidade de contração possível (MARKOVIC; JARIC, 2007), e seu treinamento tem sido considerado de grande importância para os campos do desempenho esportivo (KIRKENDALL; STREET, 1986;MALISOUX et al., 2006) e da saúde (CASEROTTI et al., 2008). Dessa forma, diferentes métodos de avaliação da potência mecânica têm sido propostos na literatura específica, com o objetivo de validá-los (MARGARIA et al., 1966;FOX;MATHEWS, 1974;BOSCO, 1983a;HARMAN et al., 1991;SAYERS et al., 1999). ...
RESUMO O objetivo do estudo foi comparar valores de potência mecânica de saltos verticais obtidos através do teste de BOSCO (potência teórica, PT) com valores de potência mecânica registrados por uma plataforma de força (potência experimental, PE) e verificar a concordância entre os dois métodos. Onze corredores recreacionais realizaram saltos contínuos máximos durante 60 segundos. Foram utilizados a plataforma de força 3D e o sistema de cinemetria 2D para cálculo da PT e PE, respectivamente. A partir da análise cinemática (Dvideow 5.0) foram obtidos o tempo de voo e o número de saltos. Utilizou-se o teste de Bland e Altman para a análise de concordância entre os métodos. Os valores médios de PT e PE foram de 15,6±2,4 W.kg-1 e 20,8±3,2 W.kg-1 , respectivamente, situando-se entre os limites de concordância de ± 2dp. Concluiu-se que a equação de PT é um método conveniente para determinação da potência mecânica durante saltos verticais contínuos. Palavras-chave: Potência mecânica. Salto vertical.
... A potência mecânica é caracterizada como a quantidade de trabalho por unidade de tempo, ou como a variação de energia mecânica produzida por unidade de tempo (CHELLY;DENIS, 2001;KYRÖLÄINEN et al., 2004;MARKOVIC;JARIC, 2007). Essa capacidade permite ao sistema neuromuscular dominar resistências com a maior velocidade de contração possível (MARKOVIC; JARIC, 2007), e seu treinamento tem sido considerado de grande importância para os campos do desempenho esportivo (KIRKENDALL; STREET, 1986;MALISOUX et al., 2006) e da saúde (CASEROTTI et al., 2008). Dessa forma, diferentes métodos de avaliação da potência mecânica têm sido propostos na literatura específica, com o objetivo de validá-los (MARGARIA et al., 1966;FOX;MATHEWS, 1974;BOSCO, 1983a;HARMAN et al., 1991;SAYERS et al., 1999). ...
The aim of this study was to compare the mechanical power values of vertical jumps measured by BOSCO test (Theoretical Power, PT) with mechanical power values registered by force plate (Experimenal Power, PE) and verify the agreement between the two methods. Eleven recreational runners performed continuous maximal jumps for 60 seconds. Force platform 3D and 2D kinematics system were used for calculation of PT and PE, respectively. Data about flight time and number of hops were obtained from the kinematic analysis (Dvideow 5.0). We used Bland & Altman for agreement between the methods. The average values of PT and PE were 15.6 ±2.4 W.kg-1 and 20.8 ±3.2 W.kg-1, respectively, ranging from the agreement limits ±2 s.d. Therefore, the equation of the PT is a convenient method for determining the mechanical power during continuous vertical jumps.
The validity and reliability of the jumping ergometer method for evaluating performance in two-legged vertical countermovement and serial rebound jumps were investigated. The internal segmental and nonvertical energy flow components for drop jumps were also studied. The exact dynamic equations governing the jumping motion in three dimensions were derived and used together with the approximate relations of the jumping ergometer method to evaluate a total of 72 vertical jumps of different types executed by 22 subjects (15 males, 7 females), average age 24.59 years. The forceplate method was selected as a reference procedure, to which the jumping ergometer results were related. For countermovement jumps, the relative error for jumping height was 3.55% (±2.92%), and for average power per kilogram body mass during the propulsion phase it was 23.79% (±4.85%). For serial rebound jumps, the respective errors were 7.40% (±4.58%) and 5.09% (±4.48%). Internal and nonvertical energy flow components amounted to about 3% of the total. It was concluded that, because of a number of invalid assumptions, unpredictable errors, and contradictory performance requirements, the validity and reliability of the jumping ergometer method for evaluating certain aspects of athletic performance are highly questionable.
Introduction.— Competitive volleyball requires powerful spring.
Methods.— To improve this skill 22 French athletes underwent jump tests aimed at mimicking this movement. Furthemore, quadriceps and hamstrings flexibility and isokinetic strength were assessed, using a Cybex 6000 dynamometer.
Results.— Though negatively correlated with age (r = 0.473), spring is positively correlated with knee flexibility (r = 0.453) and hamstrings torque acceleration energy (TAE) during concentric isokinetic contraction with 240°/s angular velocity (r = 0.464). However, quadriceps femoris concentric peak torque and hamstrings eccentric peak torque were not correlated with performance. Quadriceps femoris eccentric peak torque was not evaluated.
Conclusion.— Our results suggest that spring requires both springling (flexibility) and neuromotor coordination (TAE), thus allowing better understanding of this movement which is truly characteristic of volleyball. An approach to eccentric muscular regimen was also developed. Symmetrical results observed between the take-off foot and the other foot will enable training adjustements to improve performances and prevent muscular/tendinous lesions. These results could help guide management of various post-traumatic disorders within the frame of rehabilitation.
The aim of this study was to investigate the effects of a maximal repeated-jumps task on force production, muscle activation and kinematics, and to determine if changes in performance were dependent on gender.
Eleven male and nine female athletes performed continuous countermovement jumps for 60 s on a force platform while muscle activation was assessed using surface electromyography. Performances were videotaped and digitized (60 Hz). Data were averaged across three jumps in 10-s intervals from the initial jump to the final 10 s of the test.
No interaction between time and gender was evident for any variable; therefore, all results represent data collapsed across gender. Preactivation magnitude decreased across time periods for anterior tibialis (AT, P < .001), gastrocnemius (GAS, P < .001) and biceps femoris (BF, P = .03), but not for vastus lateralis (VL, P = .16). Muscle activation during ground contact did not change across time for BF; however, VL, G, and AT showed significant reductions (all P < .001). Peak force was reduced at 40 s compared with the initial jumps, and continued to be reduced at 50 and 60 s (all P < .05). The time from peak force to takeoff was greater at 50 and 60 s compared with the initial jumps (P < .05). Both knee flexion and ankle dorsiflexion were reduced across time (both P < .001), whereas no change in relative hip angle was evident (P = .10). Absolute angle of the trunk increased with time (P < .001), whereas the absolute angle of the shank decreased (P < .001).
In response to the fatiguing task, subjects reduced muscle activation and force production and altered jumping technique; however, these changes were not dependent on gender.
In order to evaluate physiological characteristics in young male ballet dancers, 27 boys (aged 9 to 16 years) who participated in a boys' dance course during the Kuopio Dance and Music Festival in June 1988 were studied. In general, the boys had started dancing at the age of 8.6 years and had been training for 4.1 years. They had, on average, three dancing sessions per week and the mean time spent on dancing was four hours per week. In the study, some anthropometric measurements were taken, the maximal oxygen uptake (VO2 max) was measured by a cycle ergometer test and the explosive strength and the mechanical power of lower extremities were evaluated by a jumping test. The results indicate that boys who train in ballet are in general moderately lean, have relatively small body size and a high degree of flexibility. The younger boys especially have only moderate aerobic power, but both explosive strength and mechanical power in leg muscles are good in ballet trained boys.
The purpose of this study was to compare the Wingate cycling and Bosco repeated jumps anaerobic tests. Eleven men (21.36 +/- 1.6 years; 179.1 +/- 9.3 cm; 78.7 +/- 11.0 kg) and 9 women (21.89 +/- 3.66 years; 171.8 +/- 10.0 cm; 75.9 +/- 21.4 kg), all university athletes, volunteered to participate. Subjects performed each test in random order. The tests consisted of a 30-second Wingate test and a 60-second Bosco test. The Wingate test was conducted using a Monark cycle ergometer and the Bosco test was conducted on a force platform. Following the performance of each test, peak lactate concentrations were determined. Average and peak power values were statistically greater in men and on the Bosco test. Peak lactate values were statistically greater in men but did not differ based on test. Correlations between peak lactate concentrations between tests and lactate values with peak or average power were not statistically significant. The relationship between peak power between tests was statistically significant among men, but not women. The results of the study indicated that the Bosco and Wingate tests, which both measure anaerobic characteristics, appear to measure different aspects of anaerobic power and capacity. The Bosco test also may be inappropriate for athletes who are not well trained in jumping.
In brief: Participation in soccer is increasing, possibly because many people believe that anyone can play the game. This article reviews the nature and demands of soccer and the physiological characteristics of the players, including aerobic power, anaerobic power, muscle strength, flexibility, agility, glycogen use, and fiber types. Soccer players must perform short sprints as well as cover long distances during a game. Soccer players fall in the middle of the ranges for athletes in all of the measured variables. The author concludes that soccer players are unique in their ability to repeatedly perform difficult motor skills during constantly changing tactical situations.
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.
An alternating cycle of eccentric-concentric contractions in locomotion represents a sequence when storage and utilization of elastic energy takes place. It is possible that this storage capacity and its utilization depends on the imposed stretch loads in activated muscles, and that sex differences may be present in these phenomena. To investigate these assumed differences, subjects from both sexes and of good physical condition performed vertical jumps on the force-platform from the following experimental conditions: squatting jump (SJ) from a static starting position; counter-movement jump (CMJ) from a free standing position and with a preparatory counter-movement; drop jumps (DJ) from the various heights (20 to 100 cm) on to the platform followed immediately by a vertical jump. In all subjects the SJ, in which condition no appreciable storage of elastic energy takes place, produced the lowest height of rise of the whole body center of gravity (C.G.). The stretch load (drop height) influenced the performance so that height of rise of C. of G. increased when the drop height increased from 26 up to 62 cm (males) and from 20 to 50 cm (females). In all jumping conditions the men jumped higher than the women. However, examination of the utilization of elastic energy indicated that in CMJ the female subjects were able to utilize most (congruent to 90%) of the energy produced in the prestretching phase. Similarly, in DJ the overall change in positive energy over SJ condition was higher in women as compared to men. Thus the results suggest that although the leg extensor muscles of the men subjects could sustain much higher stretch loads, the females may be able to utilize a greater portion of the stored elastic energy in jumping activities.