The psoas minor is a long, slender skeletal muscle

Skeletal muscle

Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...

 which, when present, is located in front of the psoas major muscle

Psoas major muscle

-External links: - "Posterior Abdominal Wall: Muscles of the Posterior Abdominal Wall"* *...

. This muscle does not exist in about half the human population.

Course

Psoas minor originates from the vertical fascicle

Muscle fascicle

In anatomy, a fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.Specialized muscle fibers in the heart that transmit electrical impulses from the Atrioventricular Node to the Purkinje Fibers are fascicles, also referred to as bundle branches...

s inserted on the last thoracic and first lumbar vertebrae. From there, it passes down onto the medial border of the psoas major, and is inserted to the innominate line

Linea terminalis

The linea terminalis or innominate line consists of the pectineal line, the arcuate line, and the sacral promontory.It is part of the pelvic brim, which is the edge of the pelvic inlet. The pelvic inlet is typically used to divide the abdominopelvic cavity into an abdominal and a pelvic cavity...

 and the iliopectineal eminence

Iliopectineal eminence

Medial to the anterior inferior iliac spine is a broad, shallow groove, over which the iliacus and psoas major muscles pass. This groove is bounded medially by an eminence, the iliopubic eminence , which marks the point of union of the ilium and pubis.It constitutes a lateral border of the pelvic...

. Additionally, it attaches to and stretches the deep surface of the iliac fascia

Iliac fascia

The iliac fascia is a fascia in the pelvic area of the human body.It has the following connections:* laterally, to the whole length of the inner lip of the iliac crest....

 and, occasionally, its lowermost fibers reach the inguinal ligament

Inguinal ligament

The inguinal ligament is a band running from the pubic tubercle to the anterior superior iliac spine. Its anatomy is very important for operating on hernia patients.-Anatomy:...

. Variations occur, however, and the insertion on the iliopubic eminence sometimes radiates into the iliopectineal arch

Iliopectineal arch

The Iliopectineal arch is a thickened band of fused iliac fascia and psoas fascia passing from the posterior aspect of the inguinal ligament anteriorly across the front of the femoral nerve to attach to the iliopubic eminence of the hip bone posteriorly...

.