Name
Pronunciation
(per-o-NE-us LONG-gus)
Origin/Proximal Attachment
Head of fibula
proximal two 3rd‘s of lateral surface of fibula
deep surface of the fascia cruris
the adjacent anterior & posterior crural intermuscular septa
occasionally by a few fibres from the lateral condyle of the tibia
Insertion/Distal Attachment
Plantar surface of cuboid
base of 1st (& 2nd) metatarsal
medial cuneiform (plantar surface)
Action/Relevance
Abducts & everts foot
Weakly plantar-flexes foot
Could possibly act on the leg from its distal attachment
The oblique direction of its tendon across the sole would also enable it to support the longitudinal & transverse arches of the foot
Peroneus longus & brevis come strongly into action to maintain the concavity of the foot during toe-off & tip-toeing.
Innervation
Superficial peroneal nerve (L4, 5,S1)
Notes
Superficial to Peroneus brevis
Narrow
Between its attachments to the head & shaft of the fibula there is a gap through which the common peroneal nerve passes.
The muscle belly ends in a long tendon running distally behind the lateral malleolus in a groove shared with the tendon of peroneus brevis (which lies behind it).
The groove is converted into a canal by the superior peroneal retinaculum, so that the tendons are contained in a common sheath.
The tendon runs obliquely forwards across the lateral side of the calcaneus, below the peroneal trochlea & the tendon of peroneus brevis, & beneath the inferior peroneal retinaculum.
It crosses the lateral side of the cuboid & then runs under it in a groove converted into a canal by the long plantar ligament.
It crosses the sole of the foot obliquely, & is attached by two slips to the lateral side of the base of the first metatarsal bone & the medial cuneiform.
Occassionally a third slip is extended to the base of the second metatarsal bone.
The tendon changes position at two points: below the lateral malleolus & on the cuboid bone. At both sites it is thickened & at the second a sesamoid fibrocartilage (or sometimes bone) usually develops within it.
A 2nd synovial sheath invests the tendon as it crosses the sole of the foot.