Question: what is the origin and insertion of psoas major?
Answer: The psoas major muscle is part of the iliopsoas muscle, the strongest hip flexor in the human body, and belongs to the inner hip muscles. It originates from the 1st to 4rd lumbar vertebrae, the costal processes of all lumbar vertebrae and the 12th thoracic vertebrae and inserts at the lesser trochanter of the femur.