Calf muscle anatomy


The lower leg is between the knee and the ankle. There are many muscles located in the lower leg, but three of them are the best known: the gastrocnemius and soleus , which are the most powerful muscles in the lower leg, and the tibialis anterior muscle . The Achilles tendon is also found in the lower leg.

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Bony structure of the lower leg.

The shin consists of two very strong long bones: the tibia and the fibula . The tibia, also known as tibia, is the stronger and the larger of the two. It is located closer to the middle of the lower leg. The fibula, or shin bone, is smaller and located outside of the shin.

The tibia also contains nerve fibers, including the superficial peroneal (or peroneal) nerve, the deep peroneal (or peroneal) nerve, and the tibial nerve . The main muscle in this part of the body is the gastrocnemius muscle, which gives the calf its characteristic bulge and musculature.

The anterior tibial, posterior tibial, and peroneal arteries are responsible for the blood supply to the lower leg. The lower leg makes up a major part of a person's total body weight. It is an indispensable structure for any type of weighted load such as walking, standing, running or jumping.

Common conditions that affect the shin include stress fractures , compartment syndrome , shin cramps, and muscle lacerations .

Calf muscles

The leg is divided into four sections, which contain different leg muscles: anterior, lateral, posterior, and deep posterior.

Front compartment

The anterior section at the front of the leg supports the tibialis anterior muscle, the extensor digitorum longus, the extensor pollicis longus, and the third peroneal muscle. These muscles pull the toes and feet upward, a process known as dorsiflexion .

The tibialis anterior muscle also contributes to inward rotation of the foot. You can feel these muscles contract by placing your hand on the outside of your tibia and pulling your foot up.

Side compartment

The side compartment is located on the outside of the lower leg. It contains the muscles of the peroneus longus and peroneus brevis. These muscles pull the toes and feet outward. They also help guide the foot or flex the foot . To feel the contraction of these muscles, place your hand on the outside of your lower leg and turn your foot outward.

Rear compartment

The posterior region contains large muscles known as the gastrocnemius, calf, and soleus. This compartment also contains the plantar muscle.

The calf muscle is shorter, thicker, and has two internal and external attachments. It is the most prominent of the calf muscles. Below is the soleus muscle. These three muscles attach to the Achilles tendon and all assist in plantar flexion.

Deep rear compartment

The deep posterior compartment is located deep in the back of the lower leg. It includes the tibialis posterior muscle, the flexor digitorum longus, and the flexor digitorum longus.

The tibialis posterior muscle pulls the foot inward, the flexor of the big toe flexes the toes, and the flexor longus of the big toe flexes the big toe. All three help with plantar flexion.

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