The peroneus muscles are highly variable and several variants have been noted as being occasionally present, such as "peroneus digiti minimi" and "peroneus quartus".
The opponens digiti minimi originates from the long plantar ligament and the plantar tendinous sheath of peroneus longus and is inserted on the fifth metatarsal.
If, however, it enters the tarsometatarsal joint, then it is an avulsion fracture caused by pull from the peroneus brevis.
The peroneus muscles are highly variable and several variants can occasionally be present.
These include the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius.
Tenderness may be elicited over the tendon of the peroneus longus muscle and an antalgic gait may be observed.
However, the most accurate antagonist of the tibialis anterior is the peroneus longus.
On the lateral side is commonly a tubercle called the peroneal trochlea, under which is a groove for the tendon of the peroneus longus.
