Hey, everyone! It’s Matt from Kenhub, and in this tutorial, we will discuss the origin, insertion, innervation, and function of the psoas minor muscle.
The psoas minor muscle is a long, slim muscle of the hip joint that runs ventrally to the iliopsoas. Together, they make up the inner hip muscles. The psoas minor is an inconstant muscle and is missing in 40% to 70% of all people.
In its absence, you would find a thin ligament or broadening of the medial part of the iliopsoas, so just try to sleep tonight and not think about how you may or may not have a psoas minor and how you’ll never know. You’re welcome.
If the psoas minor is present, it originates from the lateral surface of the twelfth thoracic and first lumbar vertebrae.
Distally, it’s relatively long tendon inserts on the iliopubic eminence and pectineal line of the pubis. Additionally, fibers of the insertion tendon are attached to the iliac fascia.
The innervation of the psoas minor is supplied by direct branches of the lumbar plexus. As the muscle lies deep inside the abdomen, it is not possible to be palpated from the outside.
As an inner hip muscle, the psoas minor contributes to the stabilization of the pelvis and hip joint.
A unilateral contraction bends the lumbar and vertebral column to the side, which is known as lateral flexion, while a bilateral activation bends it to the front, known as ventral flexion. All in all, this muscle’s functions show that it plays a rather subordinate role and that whether you have one or not doesn’t make a difference in the body’s ability to perform these functions.