Triceps surae muscle Triceps surae muscle The triceps surae is a pair of muscles located at the calf - the two-headed gastrocnemius and the soleus. These muscles both insert into the calcaneus, the bone of the heel of the human foot, and form the major part of the muscle of the posterior leg, commonly known as the calf muscle. The triceps surae is connected to the foot through the Achilles tendon, and has 3 heads deriving from the 2 major masses of muscle. The triceps surae is innervated by the tibial nerve, specifically, nerve roots L5–S2. Contraction of the triceps surae induce plantar
Muscle and endoneurium). This same bundles-within-bundles structure is replicated within the muscle cells. Within the cells of the muscle are myofibrils, which themselves are bundles of protein filaments. The term "myofibril" should not be confused with "myofiber", which is a simply another name for a muscle cell. Myofibrils are complex strands of several kinds of protein filaments organized together into repeating units called sarcomeres. The striated appearance of both skeletal and cardiac muscle results from the regular pattern of sarcomeres within their cells. Although both of these types of muscle contain sarcomeres, the fibers in cardiac muscle are typically branched to