Lateral Compartment of the Leg

Question 1

State the origin and insertion of peroneus longus.

Answer 1

Origin: upper 2/3 of the lateral (peroneal) surface of the shaft of the fibula extending up to its head.

Insertion: gives rise to a tendon in the lower part of the leg which overlaps the peroneus brevis and descends behind the lateral malleolus deep to the superior peroneal retinaculum with the tenon of peroneus brevis b2n it and the bone. Then it passes below the lateral malleolus deep to the inferior peroneal retinaculum on the lateral surface of the calcaneus. The tendon deviates medially to reach the sole of the foot where it runs medially and forwards in the groove on the plantar surface of the cuboid bone to reach its insertion into the lateral side of the base of the 1st metatarsal bone and adjacent part of the medial cuneiform bone. The tendon forms one of the contents of the 4th layer of the sole.

Question 2

State the nerve supply of peroneus longus.

Answer 2

Superficial peroneal nerve.

Musculocutaneous nerve

Question 3

State the actions of the peroneus longus muscle.

Answer 3

Plantar flexion of the foot.
Aversion of the foot.
It plays an important role in supporting the transverse arch of the foot.

Question 4

State the origin and insertion of peroneus brevis.

Answer 4

Origin: lower 2/3 of the lateral (peroneal) surface of the fibula, meaning the middle 1/3 is common for both peronei longus and brevis.

Insertion:
Its tendon descends closely behind the lateral malleolus grooving the bone deep to the tendon of peroneus longus and under cover of the superior peroneal retinaculum.
Then, it passes below the lateral malleolus on the lateral surface of the calcaneus deep to the inferior peroneal retinaculum to reach an insertion into the tuberosity of the base of the 5th metatarsal bone.

Question 5

State the nerve supply of the peroneus brevis.

Answer 5

Superficial peroneal nerve.

Question 6

Describe the actions of peroneus brevis.

Answer 6

Plantar flexion.
Eversion of the foot.