THE EFFECTS OF THREE DIFFERENT REAR KNEE ANGLES ON KINEMATICS IN THE SPRINT START
Journal Title: Biology of Sport - Year 2014, Vol 31, Issue 3
Abstract
The purpose of this study was to investigate the rear knee angle range in the set position that allows sprinters to reach greater propulsion on the rear block during the sprint start. Eleven university-track team sprinters performed the sprint start using three rear knee angle conditions: 90°, 115° and 135°. A motion capture system consisting of 8 digital cameras (250 Hz) was used to record kinematic parameters at the starting block phase and the acceleration phase. The following variables were considered: horizontal velocity of the centre of mass (COM), COM height, block time, pushing time on the rear block, percentage of pushing time on the rear block, force impulse, push-off angle and length of the first two strides. The main results show that first, horizontal block velocity is significantly greater at 90° vs 115° and 135° rear knee angle (p<0.05 and p<0.001 respectively) at block clearance and the first two strides; second, during the pushing phase, the percentage of pushing time of the rear leg is significantly greater at 90° vs 135° rear knee angle (p<0.01). No significant difference was found for block time among the conditions. These results indicate that block velocity is the main kinematic parameter affected by rear knee angle during the starting block phase and acceleration phase. Furthermore, the 90° rear knee angle allows for a better push-off of the rear leg than larger angles at the set position. The findings of this study provide some direction and useful practical advice in defining an efficient rear leg biomechanical configuration at the set position.
Authors and Affiliations
Chiara Milanese, Matteo Bertucco, Carlo Zancanaro
CARDIORESPIRATORY FITNESS, ACTIVITY LEVEL, HEALTH-RELATED ANTHROPOMETRIC VARIABLES, SEDENTARY BEHAVIOUR AND SOCIOECONOMIC STATUS IN A SAMPLE OF IRANIAN 7-11 YEAR OLD BOYS
The purpose of this study was to evaluate cardiorespiratory fitness (CRF), activity level, some health-related anthropometric variables, sedentary behaviour and socioeconomic status (SES) of 7-11 year old boys in the cit...
STYLE OF THINKING ABOUT DOPING AMONG SPORTSPERSONS: CHARACTERIZING THE ATTITUDES OF RISK-TAKERS AND RISK-AVOIDERS
The aim of the study is to describe the style of thinking about doping among risk-takers and risk-avoiders in three hypothetical situations varying according to the level of objective probability of an anti-doping test....
Effect of spirulina food supplement on blood morphological parameters, biochemical composition and on the immune function of sportsmen
Of highest biological value are natural concentrates of optimally combined substances produced by nature. One of food supplements of this kind is dietary Spirulina produced by the Tianshi firm (China). It is a most ratio...
Effects of endurance training on gonadal fat pad and ventricular mass in rat
It has been reported that gonadal fat pad correlates well with the body fat in mice. The effects of endurance training on gonadal fat pad and also on ventricle mass in rat were tested in this study. Eight week treadmill...
Black grape extract supplementation attenuates blood oxidative stress in response to acute exercise
The flavonoid-rich active compound in grapes is claimed to be one of the most important natural products. Hence, the objective of our research was to study parameters of the prooxidative-antioxidative balance in athletes...