The effect of triceps surae contracture force on plantar foot pressure distribution

BACKGROUND: Triceps surae contractures have been associated with foot and ankle pathology. Achilles tendon contractures have been shown to shift plantar foot pressure from the heel to the forefoot. The purpose of this study was to determine whether isolated gastrocnemius contractures had similar effects and to assess the effects of gastrocnemius or soleus contracture on midfoot plantar pressure. METHODS: Ten fresh frozen cadaver below-knee specimens were loaded to 79 pounds (350 N) plantar force with the foot unconstrained on a 10-degree dorsiflexed plate. Combinations of static gastrocnemius or soleus forces were applied in 3-lb increments and plantar pressure recordings were obtained for the hindfoot, midfoot, and forefoot regions. RESULTS: The percentage of plantar force borne by the forefoot and midfoot increased with triceps surae force, while that borne by the hindfoot decreased (p