The role of the ‘calf’ (gastrocnemius and soleus) in running – According to an article I read by Brad Beer physiotherapist posted in Running magazine-Greater than 50% of running force propulsion is generated from ‘below the knee’ ankle plantar flexor musculature. Given the force developed by the gastrocnemius complex, it is understandable that the ‘calf’ can be a potential site of muscular injury for a runner.

Many runners believe the hip musculature to be the primary force producers for running propulsion. However, researchers have shown that circa 5-10% only of force production comes from the hip musculature, with the bulk of work being done below the knee, followed by propulsive force from the knee musculature. Although the gastrocnemius has a mix of fibres, more are fast-twitch (type 2) muscle fibres allowing for explosive/powerful contractions. The soleus is primarily composed of slow-twitch (type 1 muscle fibres) and is the key muscle for endurance running. The soleus generates as a multiple of body weight 6.5-8x bodyweight, with the gastrocnemius also generating large peak muscle forces of 3.5-4.0x bodyweight.[wdi_feed id=”1″]