The principal artery of the psoas major muscle.

The psoas major m. has a complex arterial supply, derived from the lumbar, iliolumbar, obturator, external iliac and common femoral a. The branches arising from the external iliac a., though quite often multiple and slender, are represented in 75% of cases by a single large-caliber vessel. This principal artery of the psoas m. is probably responsible for the curves of the external iliac a. in the aged and also in certain competitive athletes.