Anatomy of the psoas The psoas muscle is a long, ribbon-shaped muscle that starts at your lower back, and runs down through your pelvis where it joins the iliacus and connects to the top of your thigh bone (lesser trochanters). You can’t talk or work on the psoas muscle without also mentioning the iliacus. Together, these muscles are known as the iliopsoas muscle and they form the strongest of the hip flexor muscles while also supporting your spine. #anatomy | YOGABODY

Psoas major anatomy: The psoas major is a deep muscle that originates from the transverse processes, vertebral bodies, and intervertebral discs of T12 to L5. It travels downward through the pelvic cavity, passes deep to the inguinal ligament, and inserts into the lesser trochanter of the femur. Along its course, it lies adjacent to the lumbar plexus, ureter, and abdominal aorta. It’s innervated by branches of the lumbar plexus, primarily from spinal nerves L1 to L3, and occasionally L4. Function