Kinematic and Kinetic Comparisons of Elite and Well-Trained Sprinters During Sprint Start

Abstract

The purpose of this study was to compare the main kinematic, kinetic, and dynamic parameters of elite and well-trained sprinters during the starting block phase and the 2 subsequent steps. Six elite sprinters (10.06-10.43 s/100 m) and 6 well-trained sprinters (11.01-11.80 s/100 m) equipped with 63 passive reflective markers performed 4 maximal 10 m sprint starts on an indoor track. An opto-electronic motion analysis system consisting of 12 digital cameras (250 Hz) was used to record 3D marker trajectories. At the times "on your marks," "set," "clearing the block," and "landing and toe-off of the first and second step," the horizontal position of the center of mass (CM), its velocity (XCM and VCM), and the horizontal position of the rear and front hand (X(Hand_rear) and X(Hand_front)) were calculated. During the pushing phase on the starting block and the 2 first steps, the rate of force development and the impulse (F(impulse)) were also calculated. The main results showed that at each time XCM and VCM were significantly greater in elite sprinters. Moreover, during the pushing phase on the block, the rate of force development and F(impulse) were significantly greater in elite sprinters (respectively, 15,505 +/- 5,397 N.s and 8,459 +/- 3,811 N.s for the rate of force development; 276.2 +/- 36.0 N.s and 215.4 +/- 28.5 N.s for F(impulse), p < or = 0.05). Finally, at the block clearing, elite sprinters showed a greater XHand_rear and X(Hand_front) than well-trained sprinters (respectively, 0.07+/- 0.12 m and -0.27 +/- 0.36 m for X(Hand_rear); 1.00 +/- 0.14 m and 0.52 +/- 0.27 m for X(Hand_front); p < or = 0.05). The muscular strength and arm coordination appear to characterize the efficiency of the sprint start. To improve speed capacities of their athletes, coaches must include in their habitual training sessions of resistance training.

Biomechanical structure of sprint start and effect of biological feedback methods on sprint start performance

“…There are studies indicating that sprint athletes with higher performance levels are able to generate higher propulsive forces onto the starting blocks (8,16,31,44). Mero et al (32) showed that maximal rate of force development (highest force generated within the smallest time frame) was crucial in attaining maximal block velocity.…”

“…Kinetic energy of different body parts and angular velocity of different joints were investigated in the study of Slawinski et al (44) conducted on 8 elite sprint athletes. Sixty three passive markers were placed on the reference points of athletes and each athlete performed 4 maximal 10 m sprints.…”

Análisis de la carrera de 100 metros lisos mediante la evaluación del deportista con sistema láser y plantillas instrumentadas

“…Velocidad registrada en los dos primeros apoyos de la carrera en velocistas de 100 m con videogrametría (Slawinski et al, 2010) …”

“…En Slawinski et al (2010) se observa que los velocistas de élite aplicaban un mayor impulso (N·s) que el resto de atletas de su muestra en las dos primeras zancadas, por lo que las velocidades del CM fueron mayores en el instante de despegue del pie. Sin embargo, se consideró que este mayor impulso fue influido, sobre todo, por la mayor masa corporal de estos atletas y no por el Ratio de desarrollo de la fuerza (RDF) de los mismos.…”

“…En el eje horizontal se han hallado impulsos netos en la primera zancada de 104.8 N·s en Slawinski et al (2010) en velocistas. En la segunda zancada se han hallado impulsos netos medios en el eje horizontal de 75 N·s, existiendo diferencias significativas entre los atletas de élite y los atletas bien entrenados de la muestra (Slawinski et al, 2010).…”