Triceps surae

Triceps surae is a pair of muscles located at the back of the lower leg, specifically in the calf. It is composed of two muscles, the gastrocnemius and the soleus, which both converge into the Achilles tendon.

Anatomy

The triceps surae is a two-headed muscle that lies on the posterior aspect of the lower leg. The two heads are the gastrocnemius, which is the larger and more superficial muscle, and the soleus, which is smaller and lies beneath the gastrocnemius. Both muscles merge at the lower end to form the Achilles tendon, which attaches to the calcaneus, or heel bone.

Gastrocnemius

The gastrocnemius is the larger and more superficial of the two muscles. It originates from two heads that attach to the femur, just above the knee joint. The muscle fibers descend the leg and converge into a flat tendon, which merges with the soleus muscle to form the Achilles tendon.

Soleus

The soleus is a flat, broad muscle that lies beneath the gastrocnemius. It originates from the tibia and fibula, the two bones of the lower leg. The muscle fibers ascend the leg and merge with the gastrocnemius to form the Achilles tendon.

Function

The primary function of the triceps surae is to facilitate plantar flexion of the foot, which is the movement that points the foot downward. This is an essential movement in walking, running, and jumping. The triceps surae also aids in maintaining posture by preventing the body from falling forward at the ankle joint.

Clinical significance

Injury to the triceps surae or Achilles tendon can result in significant impairment of mobility. Achilles tendinitis, a common injury among athletes, is inflammation of the Achilles tendon that can cause pain and swelling in the lower leg. In severe cases, the Achilles tendon can rupture, requiring surgical repair.