Definition
The musculus psoas is a hip muscle and consists of the musculus psoas major and in half of the people also of the musculus psoas minor. Since the Musculus Psoas Major is attached to the Musculus Iliacus in its course, it is also often called Musculus Iliopsoas. The Musculus Psoas Major is one of the large muscles of the lower extremity and belongs to the front group of the rear hip muscles.
History
The base of the musculus psoas major is divided into two parts.
- Once it originates from the lateral surface of the twelfth thoracic vertebra, the first four lumbar vertebrae and the intervertebral discs.
- The second part originates from the transverse processes of lumbar vertebral bodies one to five. The Musculus Psoas Major then merges with the Musculus Iliacus and moves as Musculus Iliopsoas through the Lacuna musculorum (a muscle port) to the thigh bone and then sets at the Trochanter minor which is a small extension of the thigh bone.
Function
In the hip joint, the muscle has the following functions: it bends (flexion) it turns the leg outwards (external rotation) lateral inclination with one-sided tension (lateral flexion)
- He bends (flexion)
- It turns the leg outwards (external rotation)
- Lateral tilt with one-sided tension (lateral flexion)
Sensitive supply of the M. psoas major
The musculus psoas major is innervated by the nervus femoralis. In addition, direct branches from the plexus lumbalis (L 1-4) pull into the muscle and partially innervate it as well.
Psoas sign
The psoas sign is a sign of appendicitis. If you bend one leg in the hip, this movement causes pain, the psoas sign is positive.
Musculus psoas minor
The musculus psoas minor is, as the name suggests, the small psoas muscle. It is not pronounced in every person and has hardly any function. It originates from the twelfth thoracic vertebra and the first lumbar vertebra.
The M. Psoas Minor consists of a long tendon that radiates into the Musculus Iliopsoas. Like the Psoas Major muscle, it attaches to the Trochanter Minor of the femur. The muscle is innervated by the lumbar nerves 1-3.
