Lower limb

Ankle retinacula (Extensor, flexor, and fibular / peroneal retinacula)

Retinacula musculorum extensorum, flexorum et fibularium pedis

Origin

Distal tibia, fibula, lateral calcaneus (sinus tarsi), and deep crural fascia

Insertion

Calcaneus, navicular, medial cuneiform, and plantar fascia

Function

Prevents bowstringing of ankle tendons: Extensor retinacula (superior and cruciate inferior) retain tibialis anterior/EHL/EDL; Flexor retinaculum forms the tarsal tunnel roof; Fibular (peroneal) retinacula secure fibularis longus/brevis behind lateral malleolus

Innervation

Superficial fibular, sural, and tibial nerves (L4–S2)

Movement & chain

Optimizes mechanical excursion of extrinsic leg muscles

Palpation

Palpable across anterior ankle crease, posterior to medial malleolus, and behind lateral malleolus

Clinical

Tarsal tunnel syndrome (tibial nerve compression causing plantar burning and paresthesia; positive Tinel sign); Peroneal tendon subluxation/dislocation (superior fibular retinacular tear); anterior extensor friction tenosynovitis.

Segmental innervation

L4–S2

In clinical practice

Tinel test for tarsal tunnel, peroneal tendon stabilization bracing, and surgical retinacular reconstruction

Region in the model

Lower limb