The differences in dynamic stiffness and co-contraction between walking, running and cycling at equivalent intensities

A large dynamic joint stiffness (DJS) has been associated with skeletal injury, while a lower DJS has been associated with an increase in soft tissue injury [1]. Increased Co-contraction indices (CCI) have been linked to increased joint contact forces [2]. DJS and CCI were calculated to determine how these variables relate to injury risk in running and cycling. Running had a higher DJS and, for most muscle groupings, a larger co-contraction index compared to walking and cycling. Despite lower co-contraction, the antagonistic muscle activity at the large peak flexion angles experienced while cycling may help explain overuse injury in cycling.