Binstead Justin T., Munjal Akul, Varacallo Matthew A.
Medical College of Georgia
Penn Highlands Healthcare System
The calf (Latin: sura) refers to the posterior portion of the lower leg. The two largest muscles in this region include the gastrocnemius and the soleus. The gastrocnemius is the most superficial of the muscles and has two heads, medial and lateral. The two heads of the gastrocnemius converge and form a confluent muscle belly. The lateral head originates from the lateral surface of the lateral femoral condyle and the medial head from the posterior, non-articular aspect of the medial femoral condyle. The muscle belly of the gastrocnemius joins the soleus muscle distally to form the calcaneal tendon (i.e. the achilles tendon), which inserts onto the posterior calcaneus. The calf muscle plantarflexes the ankle joint and is innervated by the tibial nerve. The soleus is a large, flat muscle located deep to the gastrocnemius. The plantaris is a relatively small muscle with an appreciably long tendonous portion. The tendinous portion can easily be mistaken for a nerve. The plantaris muscle arises from the lateral supracondylar line of the femur and is completely absent in up to 10% of the population. The muscle descends medially, eventually forming into a tendon that runs down the leg, between the gastrocnemius and soleus. This tendon blends with the calcaneal tendon.
小腿（拉丁语：sura）指的是小腿的后部。该区域最大的两块肌肉是腓肠肌和比目鱼肌。腓肠肌是最浅表的肌肉，有内侧和外侧两个头。腓肠肌的两个头会合形成一个融合的肌腹。外侧头起自股骨外侧髁的外侧面，内侧头起自股骨内侧髁的后部非关节面。腓肠肌的肌腹在远端与比目鱼肌相连，形成跟腱，附着于跟骨后部。小腿肌肉使踝关节跖屈，由胫神经支配。比目鱼肌是一块大的扁平肌肉，位于腓肠肌的深部。跖肌是一块相对较小的肌肉，有相当长的肌腱部分。肌腱部分很容易被误认为是神经。跖肌起自股骨的外侧髁上缘，在多达10%的人群中完全缺失。该肌肉向内侧下行，最终形成一条肌腱，沿小腿下行，位于腓肠肌和比目鱼肌之间。这条肌腱与跟腱融合。
