Mechanical determinants of 100-m sprint running performance

Jean-Benoît Morin (1) , Muriel Bourdin (2) , Pascal Edouard (1) , Nicolas Peyrot (3) , Pierre Samozino (1) , Jean-René Lacour (2)

1 LIBM - Laboratoire Interuniversitaire de Biologie de la Motricité
2 LBMC UMR T9406 - Laboratoire de Biomécanique et Mécanique des Chocs
3 DIMPS - Déterminants Interculturels de la Motricité et de la Performance Sportive

Sprint mechanics and field 100-m performances were tested in 13 subjects including 9 non-specialists, 3 French national-level sprinters and a world-class sprinter, to further study the mechanical factors associated with sprint performance. 6-s sprints performed on an instrumented treadmill allowed continuous recording of step kinematics, ground reaction forces (GRF), and belt velocity and computation of mechanical power output and linear force–velocity relationships. An index of the force application technique was computed as the slope of the linear relationship between the decrease in the ratio of horizontal-to-resultant GRF and the increase in velocity. Mechanical power output was positively correlated to mean 100-m speed (P<0.01), as was the theoretical maximal velocity production capability (P<0.011), whereas the theoretical maximal force production capability was not. The ability to apply the resultant force backward during acceleration was positively correlated to 100-m performance (rs>0.683; P<0.018), but the magnitude of resultant force was not (P = 0.16). Step frequency, contact and swing time were significantly correlated to acceleration and 100-m performance (positively for the former, negatively for the two latter, all P<0.05), whereas aerial time and step length were not (all P>0.21). Last, anthropometric data of body mass index and lowerlimb- to-height ratio showed no significant correlation with 100-m performance. We concluded that the main mechanical determinants of 100-m performance were (1) a ‘‘velocity-oriented’’ force–velocity profile, likely explained by (2) a higher ability to apply the resultant GRF vector with a forward orientation over the acceleration, and (3) a higher step frequency resulting from a shorter contact time.

Mots clés: Performance; Force–velocity; Power output; Ground reaction force application

Domaines: Biomécanique [physics.med-ph]; Biomécanique [physics.med-ph]

Jean-Benoît Morin, Muriel Bourdin, Pascal Edouard, Nicolas Peyrot, Pierre Samozino, et al.. Mechanical determinants of 100-m sprint running performance. European Journal of Applied Physiology, 2012, 112 (11), pp.3921-3930. ⟨10.1007/s00421-012-2379-8⟩. ⟨hal-00908318⟩