Calf muscles

Calf muscles - The muscles extending from the back of the knee to the heel. The gastrocnemius muscle starts behind the knee and forms the bulky part of the calf; under it is the soleus muscle which starts at the back of the tibia (shin).

The 2 muscles join to form the Achilles tendon, which connects them to the heel. Contraction of the calf muscles pulls the heel up and is important in walking, running, and jumping.

Pain in these muscles occurs because of cramp, sciatica, or, more rarely, deep vein thrombosis. The calf muscles may be affected by claudication (pain caused by walking and relieved by rest).