ABSTRACT BACKGROUND: We examined the kinetic and kinematic variables and postural characteristics of horizontal, inclined, and declined maximum sprint running.
METHODS: Ten physically active men performed two maximal sprints at each condition (0% [0°]; ±5% [2.86°]; ±10% [5.71°]).
RESULTS: During the +10% condition, the ankle was significantly more plantar-flexed (P<0.05) during the swing phase and the knee joint was more extended (P<0.05) during the mid-stance phase and after toe-off than in horizontal level sprinting. Regarding the kinetic variables, we observed significant ground reaction force differences in ±10% (5.71°) sprinting compared to horizontal sprinting. As the slope angle changed from uphill (+10% [5.71°]) to downhill (-10% [5.71°]), we observed increased vertical impact force peaks, unchanged vertical active force peaks, increased anterior-posterior braking forces, and unchanged anterior-posterior propulsive forces.
CONCLUSIONS: The knee and hip joint moments differed significantly between uphill and horizontal sprinting. Thus, such surfaces (excluding -10% level sprinting) are recommended in sports training, as they lead to improvement in biomechanical characteristics (force output, step length, and step frequency), which are tightly connected with sprinting performance. The -10% condition exhibited increased injury likelihood given the higher vertical force impact peaks and higher breaking forces; thus, it is not recommended for sprint training.
SOURCE: Savvas P. Dimitriadis, Marco Canolintas, and Samuel J. Allen. 2022. Uphill and downhill sprinting: a biomechanical study of kinetic and kinematic variables. Gazzetta Medica Italiana – Archivio per le Scienze Mediche 2022 October;181(10):703-16. DOI: 10.23736/S0393-3660.21.04714-8
