The popliteus muscle contributes to pain and stiffness behind the knee. The muscle is particularly affected by PCL injury and repair surgery.
The plantaris muscle is a very small muscle located behind the knee. It contributes to pain behind the knee and is occasionally involved in cramps in the calf.
The flexor digitorum longus muscle contributes to pain in the foot and lower leg. It plays a role in foot cramps, hammertoes, and claw toes.
The tibialis posterior muscle contributes to pain in the lower leg above the heel. This pain will often descend into the heel and the bottom of the foot. The pain may radiate into the lower calf. Dysfunction in muscle contributes to fallen arches and weak ankles that collapse inward.
The gastrocnemius muscle contributes to pain in the back of the knee, lower leg, ankle, and foot arch pain. The muscle is known to contribute to lower leg cramps.
The soleus muscle can cause and contribute to pain in the heel, ankle, and back of the knee. It can also cause pain in the low back on the same side of the affected leg. Dysfunction of the soleus muscle can also contribute to swelling in the foot and ankle. Occasionally a trigger point at the bottom and outside of the muscle can contribute to pain in the jaw and side of the head.