The psoas, also known as the iliopsoas, is a major muscle of the human body located deep within the abdomen. It is composed of two muscles: the psoas major and the iliacus.
The psoas major originates from the lumbar vertebrae, specifically T12 through L5, and extends down towards the pelvis. It then joins with the iliacus, a muscle located in the pelvic region, to form a common tendon called the iliopsoas. This tendon inserts into the lesser trochanter of the femur, which is a bony prominence located at the top part of the thigh bone.
Functionally, the psoas muscle plays a crucial role in hip flexion, allowing the thigh to bend towards the chest. It is essential for activities such as walking, running, and climbing stairs. Additionally, the muscle also assists in lateral and medial rotation of the hip joint.
Due to its deep position, the psoas is not easily palpable or visible, making it challenging to isolate during physical examination. However, it can become strained or tight with certain repetitive movements or poor posture, leading to discomfort or lower back pain. Consequently, stretching and strengthening exercises are often recommended to maintain its flexibility and prevent potential musculoskeletal issues.
In summary, the psoas is a deep abdominal muscle formed by the psoas major and iliacus muscles. It plays a significant role in hip flexion and overall lower body movement.
