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 popliteus muscle can cause and contribute to pain behind the knee. Prime indicators of popliteus dysfunction is an inability to lock the knee and/or you find your pain behind the knee worsens when walking downstairs or an incline. Pain from the popliteus muscle often mimics meniscus and other knee ligament and tendon injury pain.
The gastrocnemius muscle is a prime contributor to pain in the back of the knee. It can contribute to lower leg, ankle, and arch pain.
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.