Part 8: Lateral Compartment of Leg

Question 1

What are the boundaries of the lateral compartment?

Answer 1

Anterior: AIMS
Posterior: PIMS
Medial: Surface
Superficial: Deep fascia

Question 2

What are the muscles of the lateral compartment?

Answer 2

Peroneus longus and peroneus brevis

Question 3

What is the origin, insertion, action and innervation of peroneus longus

Answer 3

O: Upper 2/3 lateral shaft of fibula, head and superficial TF joint
I: Planter aspect base of 1st MT, medial cuneiform, passing deep to longitudinal plantar ligament
A: Plantarflexion and eversion. Supports lateral longitudinal and transverse arches
N: Superficial peroneal nerve

Question 4

What is the origin, insertion, action and innervation of peroneus brevis

Answer 4

O: Lower 2/3 lateral shaft of fibula
I: Tuberosity of base of 5th MT
A: Plantarflexion and everts foot. Supports lateral longitudinal arch
N: Superficial peroneal nerve

Question 5

What binds the tendons in place around malleoulus?

Answer 5

Superior peroneal retinaculum (tip of mal - calcaneus) + inferior peroneal retinaculum (peroneal trochlear to calcaneus)
Both tendons are enclosed in common synovial sheath

Question 6

Which tendon is deeper - brevis or longus?

Answer 6

Brevis - broad tendon in contact with lateral mal, narrow longus tendon lies on brevis and does not contact mal