What are the main muscle groups in the posterior compartment of the leg?

The posterior leg contains two muscle groups: the superficial group (gastrocnemius, soleus, plantaris) for plantar flexion, and the deep group (popliteus, flexor digitorum longus, flexor hallucis longus, tibialis posterior) for toe flexion, foot inversion, and stabilization. All are supplied by the tibial nerve.

What is the function of the gastrocnemius muscle?

The gastrocnemius is a powerful plantar flexor of the foot when the knee is extended. It also flexes the knee and is involved in fast movements like running.

How do the gastrocnemius and soleus muscles differ in function?

Both plantar flex the foot, but gastrocnemius acts with knee extended and is key for running/jumping, while soleus is a powerful plantar flexor for standing/walking and stabilizes the leg on the foot.

What is the role of the popliteus muscle?

The popliteus unlocks the extended knee by laterally rotating the femur. It also retracts the lateral meniscus during knee movement.

Which muscles support the arches of the foot?

Flexor digitorum longus supports longitudinal arches, flexor hallucis longus supports the medial arch, and tibialis posterior supports medial and transverse arches.

What is 'tennis leg' and which muscle is involved?

Tennis leg is a tear of the medial gastrocnemius at its musculotendinous junction. It typically occurs during sudden stretching, such as in sports activities.

Why is the plantaris muscle often used in tendon grafting?

The plantaris has a long tendon and is considered vestigial, making it suitable for harvesting in surgical repairs without significant functional loss.

What is the common insertion point for the superficial posterior leg muscles?

The gastrocnemius, soleus, and plantaris all insert via the tendocalcaneus (Achilles tendon) into the posterior calcaneus.

Posterior Leg Muscles – Gastrocnemius, Soleus & Deep Flexors

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