By Jordana Bieze Foster
Increasing running speed in recreational runners has greater kinetic effects at the ankle than the knee, according to research from Denmark that may have implications for injury prevention.
In 33 recreational runners, investigators from Aarhus University found that running at 16 km/h was associated with a mean peak plantar flexion moment .74 Nm/kg higher than running at 8 km/h; the same increase in running speed was associated with a .52 Nm/kg increase in mean peak knee extension moment.
The findings, epublished on September 16 by Clinical Biomechanics, suggest that recreational runners experiencing pain related to the plantar flexors may benefit from reducing their running speed.
In a related modeling study, researchers from the University of Melbourne found that the contribution of tendon elastic strain energy to positive work in the ankle plantar flexors increased significantly with increases in running speed. Those findings were published in the September issue of the Journal of Experimental Biology.
Petersen J, Nielsen RO, Rasmussen S, Sorensen H. Comparisons of increases in knee and ankle joint moments following an increase in running speed from 8 to 12 to 16 km/h. Clin Biomech 2014 Sep 16. [Epub ahead of print]
Lai A, Schache AG, Lin Y-C, Pandy MG. Tendon elastic strain energy in the human ankle plantar flexors and its role with increased running speed. J Exp Biol 2014;217(Pt 17):3159-3168.