Effect of Running Speed on Lower Limb Joint Kinetics

TLDR

Knowledge of lower‑limb muscle function across running speeds is essential for understanding human high performance and identifying injury‑related factors. The study evaluated how running speed affects lower‑limb joint kinetics in eight participants running at four discrete speeds on an indoor synthetic track. Using inverse dynamics, 33 torque, power, and work variables at the hip, knee, and ankle were computed and statistically analyzed for speed effects, revealing distinct joint torque profiles across anatomical planes. Higher running speeds produced the greatest increases in sagittal‑plane hip and knee torques, powers, and work during terminal swing, while knee stance work remained unchanged and ankle stance work plateaued after 5.02 m·s; hip extensor and knee flexor loads rose most dramatically toward maximal sprinting.

Abstract

Knowledge regarding the biomechanical function of the lower limb muscle groups across a range of running speeds is important in improving the existing understanding of human high performance as well as in aiding in the identification of factors that might be related to injury. The purpose of this study was to evaluate the effect of running speed on lower limb joint kinetics.Kinematic and ground reaction force data were collected from eight participants (five males and three females) during steady-state running on an indoor synthetic track at four discrete speeds: 3.50±0.04, 5.02±0.10, 6.97±0.09, and 8.95±0.70 m·s. A standard inverse-dynamics approach was used to compute three-dimensional torques at the hip, knee, and ankle joints, from which net powers and work were also calculated. A total of 33 torque, power, and work variables were extracted from the data set, and their magnitudes were statistically analyzed for significant speed effects.The torques developed about the lower limb joints during running displayed identifiable profiles in all three anatomical planes. The sagittal-plane torques, net powers, and work done at the hip and knee during terminal swing demonstrated the largest increases in absolute magnitude with faster running. In contrast, the work done at the knee joint during stance was unaffected by increasing running speed, whereas the work done at the ankle joint during stance increased when running speed changed from 3.50 to 5.02 m·s, but it appeared to plateau thereafter.Of all the major lower limb muscle groups, the hip extensor and knee flexor muscles during terminal swing demonstrated the most dramatic increase in biomechanical load when running speed progressed toward maximal sprinting.