Overview
Triangular muscle whose fleshy part arises from the coxal tuber (the "point of the hip") and fills the angle between the superficial gluteal and the quadriceps. In the horse its caudal border is joined to the cranial head of the superficial gluteal. Distally it continues into the fascia lata, the thick fascia of the lateral thigh.
Origin
Coxal tuber (tuber coxae).
Insertion
Fascia lata and, through it, the patella, lateral patellar ligament and tibial crest.
Action
Flexes the hip and extends the stifle by tensing the fascia lata.
Innervation
Cranial gluteal nerve (n. gluteus cranialis).
Clinical relevance
The coxal tuber from which it arises is very prominent in the horse and fractures easily from knocks against door frames or in falls. The resulting "knocked-down hip" leaves the croup asymmetric when seen from behind.