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Dance has attracted little scientific interest on the effects of physical fitness improvements on performance and injury severity, particularly with respect to contemporary dance. The main aims of the current work were: a) to observe the physical demands of dance performance; b) to develop a reliable dance-specific performance tool; c) to assess the association between selected physical fitness parameters and performance in contemporary dance by using a new reliable method (AC test); d) to assess selected physical fitness parameters in relation to injury severity in contemporary dance; e) to study the effects of increased fitness parameters on performance through a randomized controlled trial. A total of 50 performances, performed by 20 dancers, were monitored by using a portable accelerometers (SWA armbands) and heart rate monitors while 45 performances in DVDs were video analysed. Six dancers and two dance teachers were recruited to test a newly developed performance tool. A sample made of 41 dancers were recruited and assessed for aerobic fitness (DAFT), lower body muscular power (jump height test), upper body muscular endurance (press-ups test), flexibility (active and passive hip ROM), body composition (skinfolds), performance (n=17) and injury severity (n=16). In order to investigate the effects of the supplementary fitness training on performance, 24 of the total 41 dancers, were randomly assigned to either an intervention (n=12) or control (n=12) group. The intervention group undertook a specifically designed exercise-training programme (circuit and WBV training) lasting six weeks. Both groups were re-tested for physical fitness levels and performance at the end of the intervention period. Results revealed that performance intensities varied from light to moderate while these were observed with the use of pliés and jumps as well as lifting other dancers. Based on the seven most frequently used criteria by selected pre-professional contemporary dance institutions and companies, a novel performance tool (AC tool) was developed with an inter-rater reliability of r=0.96. There was a significant correlation between aesthetic competence (AC) scores and jump ability (r=0.55) and press-ups (r=0.55), respectively. Stepwise backward multiple regression analysis revealed that the best predictor of AC was press-ups (R2=0.30, p=0.03, 95% confidence intervals=0.11–1.34). Univariate analyses also revealed that the interaction of press-ups and jump ability improved the prediction power of AC (R2=0.44, p=0.004, 95% confidence intervals=0.009–0.04). Pearson’s correlation coefficients detected significant negative correlations between the mean score recorded for injury severity (expressed as TDO) and lower body muscular power (r=-0.66; p=0.014); backward regression analysis also revealed that, from all studied parameters, the strongest predictor of TDO was lower body muscular power (p=0.014). For the intervention group repeated measures ANOVA revealed significant increases (pre vs. post) in aerobic fitness (p<0.05), lower body muscular power (p<0.05), upper body muscular endurance (p<0.05) and performance (p<0.05). Linear regression analyses indicated that the only significant predictor of AC was aerobic capacity (F=7.641; p=0.03); the interaction of press-ups and aerobic capacity (F=6.297; p=0.036), and lower body muscular power with aerobic capacity (F=5.543; p=0.05) demonstrated an improved prediction power. These results show that the observed contemporary dance performance is an intermittent type of activity of moderate intensity. Given the reliability of the AC tool, it is concluded that upper body muscular endurance and jump ability best predict AC of contemporary dancers. Reduced lower body muscular power is associated with increased severity of injuries. Finally, supplementary exercise training significantly increases lower body muscular power, upper body muscular endurance and aerobic fitness, which in turn are beneficial to improve AC of contemporary dancers.

Background: Training to increase muscular power is essential for improving athletic performance in most sports. Weight training (WT) is a common means for training muscular power. Another modality, flywheel resistance training (FRT), may be superior for improving muscular power. However, few studies have examined if FRT is kinematically similar to WT, or if FRT kinematics change with increasing inertial load. The purposes of this study were to determine how sagittal plane joint kinematics are affected by increasing inertial load during FRT squats, and to determine how FRT squat joint kinematics compare to WT squat joint kinematics. Methods: Subjects (n=9) completed three visits for this study. On the first visit subjects completed squat 1 repetition maximum (1RM) testing. The second visit served as a full FRT familiarization session in which subjects performed one set of 5 maximal effort FRT squats at each inertial load (0.050, 0.075, and 0.100 kgm2). On the third visit, subjects were videoed in the sagittal plane while performing the FRT squat protocol. Subjects then completed 5 maximal velocity repetitions of WT squats with the barbell loaded according to the Kansas Squat Test (KST) protocol. Kinematic differences between inertial loads were determined via 1-way repeated measures ANOVAS while differences between FRT and WT were determined with paired T-tests. Results: There were no differences in peak sagittal plane knee, trunk-hip, trunk (absolute) or ankle angles between inertial loads. Peak and mean joint angular velocities decreased with increasing inertial loads at the knee and trunk-hip. Mean joint angular velocities decreased at the ankle with increasing inertial loads, while peak and mean trunk (absolute) angular velocities were unaffected. No statistical analyses were conducted for FRT and WT comparison as not enough subjects met the criteria (n=3). Conclusions: Sagittal plane joint kinematics are largely maintained despite increasing inertial load during FRT squats. Lower extremity joint angular velocities decreased with increasing inertial load. If training for muscular power and knee extensor velocity is the goal, then the inertia of 0.050 kgm2 is most suitable.

Introdução: No Karatê o chute frontal Mae geri é considerado uma técnica de simples execução, porém muito eficiente e muito utilizada em competições. Os fundamentos do Karatê descrevem que o melhor desempenho do chute será alcançado quando as forças de todas as partes do corpo forem utilizadas simultaneamente, do centro do corpo para as extremidades, o que parece ser suportado pelo princípio biomecânico de coordenação de impulsos parciais. Para que o chute seja eficiente e atinja a máxima velocidade, a transferência de energia mecânica entre os segmentos deve acontecer de tal maneira que os segmentos envolvidos no golpe se movimentem dentro de uma sequência no sentido proximal-distal. Objetivos: O presente estudo tem como objetivo geral avaliar parâmetros cinemáticos e cinéticos do Mae geri para compreender a dinâmica do golpe realizado por caratecas de diferentes níveis de treinamento. Método: Doze caratecas do grupo faixa preta (12,75 ± 8,91 anos de prática) e sete caratecas do grupo faixa branca (1,18 ± 0,88 anos de prática) executaram o Mae geri. Com os dados de cinemática dos segmentos (pelve, coxa, perna e pé) do membro inferior de ataque e de força de reação do solo foram calculadas as velocidades lineares, velocidades angulares, os torques, as potências e as transferências de energia entre os segmentos. Resultados: No grupo faixa preta as magnitudes de velocidade linear dos segmentos foram significativamente maiores do que no grupo faixa branca, resultando em menor duração total do golpe no grupo faixa preta. O Mae geri do grupo faixa preta é caracterizado no início do golpe por uma transferência de energia mecânica dos segmentos distais para os segmentos proximais de todas articulações analisadas (quadril, joelho e tornozelo), com maior magnitude de energia mecânica sendo transferida do pé para a perna, ainda com o pé no chão. Após tirar o pé de ataque do chão, a transferência de energia mecânica da coxa para a pelve apresenta um aumento de magnitude. No último terço do golpe, há uma transferência de energia mecânica da perna para a coxa na articulação do joelho e da perna para o pé na articulação do tornozelo. O grupo faixa branca tem um comportamento diferente de transferência de energia mecânica entre os segmentos comparado ao grupo faixa preta, principalmente no último terço do golpe. Além disso, magnitudes de geração de potência pelos músculos para os segmentos, de absorção de potência pelos músculos a partir dos segmentos e transferência de energia mecânica entre segmentos foram significativamente maiores no grupo faixa preta. Conclusão: Os resultados sugerem que a transferência de energia mecânica entre os segmentos permite que caratecas faixa preta executem o Mae geri de acordo com os princípios biomecânicos de coordenação dos impulsos parciais, respeitando uma sequência de movimentos no sentido proximal-distal. O nível de treinamento dos caratecas implica em diferenças no comportamento das velocidades dos segmentos e na transferência de energia entre os segmentos, o que influencia na eficiência e no desempenho do golpe / Introduction: In karate the Mae geri front kick is considered a simple execution technique, however very efficient and widely used in competitions. The karate\'s fundamentals describe that the best kick performance will be achieved when the strengths of all parts of the body are used simultaneously, from the body\'s center to outside, which seems to be supported by the biomechanical principle of partial impulse coordination. In order for the kick to be efficient and reach maximum speed, the mechanical energy transfer between segments must occur in such a way that the segments involved in the stroke move within a sequence in the proximal-distal direction. Purpose: The present study has as general purpose to evaluate kinematic and kinetic parameters of the Mae geri to understand the dynamics of the stroke made by karate practitioners of different levels of training. Method: Twelve karate practitioners of black belt group (12,75 ± 8,91 years of practice) and seven karate practitioners of white belt group (1,18 ± 0,88 years of practice) performed the Mae geri. With the kinematics data of the segments (pelvis, thigh, leg and foot) of the lower attack member and the ground reaction force were calculated the linear velocities, angular velocities, the moments of force, the powers and the mechanical energy transfer between segments. Results: At black belt group the linear velocity magnitudes of segments were significantly higher than in the white belt group, resulting in a shorter total stroke duration in the black belt group. The Mae geri of the black belt group is characterized at the beginning of the stroke by a transfer of mechanical energy from the distal segments to the proximal segments of all joints analyzed (hip, knee and ankle), with higher magnitude of mechanical energy being transferred from the foot to the leg, still with the foot on the ground. After removing the attack foot on the ground, the mechanical energy transfer from the thigh to pelvis presents an increase of magnitude. At the last third of the stroke, there is a mechanical energy transfer from the leg to the thigh at the knee joint and from the leg to the foot at the ankle joint. The white belt group has a different behavior of mechanical energy transfer between the segments compared to the black belt group, specially at the last third of the stroke. Besides that, magnitudes of power generation by the muscles to the segments, power absorption by the muscles from the segments and mechanical energy transfer between segments were significantly higher in the black belt group. Conclusion: The results suggest that the transfer of mechanical energy between segments allows black belt karate practitioners perform the Mae geri according to the biomechanical principles of the coordination of partial impulses, respecting a sequence of movements in the proximal-distal direction. The training level of the karate practitioners implies in differences in the behavior of the velocities of the segments and in the mechanical energy transfer between segments, which influences the efficiency and the performance of the stroke

Soccer players change direction repeatedly throughout a game, making agility an important component of their performance. The purpose of this project was to identify how anatomical and physical characteristics influence agility performance among soccer players. The influences of anthropometry, strength, and power on agility performance in soccer players were investigated. The participants were NCAA Division I soccer players (N = 65). Anthropometric measures included height, body mass, percent body fat, lean body mass. Strength was evaluated using an isometric mid-thigh pull, and power was measured by vertical jumps. In correlation analysis, agility performance showed a statistically significant correlation (p<0.05) with peak power (PP) from 0kg and 20kg counter-movement jumps (r=-.379 & r=-.364 respectively) for the male players. Also for the males, percent body fat showed significant correlations (p<0.05) with Average 2 (r=-.438), 3 (r=-.411), and All (r=-.436). I conclude that the anthropometric measures evaluated have little influence on agility performance.

To assess acute performance-related effects of foam rolling, this study investigated the immediate effects of a standard foam rolling protocol on explosive strength of the plantarflexors and alpha motor neuron excitability in the soleus. Explosive strength was measured via vertical jump height (JUMP) and the Reactive Strength Index (RSI) obtained from a single leg drop jump. Alpha motor neuron excitability was measured by H reflex amplitude as H wave to M wave ratio (HM) obtained from the soleus muscle. JUMP and RSI measures were analyzed from nineteen subjects (12 male, 7 female) HM data were analyzed from 15 subjects (9 male, 6 female). Subjects attended one day of practice and instruction for the single leg drop jump and one day for data collection. One leg was randomly assigned to be the test leg (FL) and the other as the control (NL). The reported dominant leg and gender were also recorded for each subject. Subjects performed two single leg drop jumps per leg from a box height of 30 cm and then 10 soleus H reflexes were obtained. The intervention, which followed standard professional guidelines, consisted of 2.5 minutes of foam rolling for the FL and rest for the NL, followed by a 5 minute warm up on a cycle ergometer. The best jump and the average HM ratio were chosen for analysis. For each variable a post/pre ratio was calculated for statistical analysis. A 2x2x2 factor ANOVA with repeated measures on both factors was used for each variable. Analysis revealed no statistically significant differences for any of the variables, either as main effects or any of the interaction effects. Subjects trended towards a slightly larger post-intervention decrease in JUMP and RSI for the FL than the NL but this was not significant. It was concluded that a 2.5 minute intervention of foam rolling had no acute effect on explosive strength of the plantarflexors or alpha motor neuron excitability of the soleus. / text

Subject: Active senior lifestyle Author's name: Bc. Iveta Dušková Supervizor: profesor Ing. Václav Bunc CSc. Objective: To verify whether biological age of tested seniors is in line with their calendar age. The differnce towards calendar age will be evaluated via ECM/BCM ration based on body content analysis. I will investigate the influence of physical activity on slower ageing physiology and the effect of physical activity on status of net muscle mass and on frequency of civilazation diseases. The goal is to figure out if active lifestyle is available also for seniors. Methods: The core of the work is qualitative and quantitative survey mapping antropometric parameters by bioimpedancy method. The functional values were collected by motorical step est and by handgrip. Further the subjective quality life judgment interview with yes/no options was used for the target senior group. Results: The relationship was found for the bioimpedancy results and the the volume of physical weekly activity (in hours) and level of BMI and pecentage of body fat. Further the realtionship was found for physical activity volume and for the dynamometric and motorical test results. Thjere is a difference between men and women. There was no relationship found for ECM/BCM coefficient and physical activity volume. The type...