Corpus3D

Lower limb

Common tendon sheath of fibularis muscles

Vagina tendinum musculorum fibularium communis et plantaris

Origin
Begins ~4 cm proximal to the lateral malleolus on the posterior distal fibula
Insertion
Passes behind the lateral malleolus under the superior fibular retinaculum, bifurcates at the peroneal trochlea under the inferior retinaculum, with fibularis longus continuing into the deep sole
Function
Enables smooth frictionless movement of the fibularis longus and brevis tendons around the acute lateral malleolar pivot
Innervation
Sensory branches from the superficial fibular and sural nerves
Movement & chain
Heavily stressed during lateral cutting maneuvers and ankle push-off
Palpation
Palpable directly behind and beneath the lateral malleolus
Clinical
Peroneal tendon subluxation/dislocation (rupture of the superior peroneal retinaculum during inversion ankle sprain with audible/palpable snapping); peroneal tenosynovitis
Segmental innervation
L5, S1 spinal roots
In clinical practice
Ankle stability testing, retromalleolar grooving/retinacular repair for recurrent subluxation, wobble-board proprioceptive rehabilitation
Region in the model
Lower limb

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