Iliopsoas - Audio Lecture 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The iliopsoas is a muscle in the anterior compartment of the thigh. It is comprised of two separate muscles; the psoas major and iliacus. These muscles arise in the pelvis and pass under the inguinal ligament into the anterior compartment of the thigh – where they form a common tendon. Attachments: Psoas major – originates from the lumbar vertebrae Iliacus – originates from the iliac fossa of the pelvis. They insert together onto the lesser trochanter of the femur. Actions: Flexion of the the thigh at the hip joint. Innervation: Psoas major – anterior rami of L1-3 Iliacus – femoral nerve. Blood supply: Iliolumbar branch of the internal iliac artery, with contributions from the obturator and femoral arteries. By TeachMeSeries Ltd (2026) Fig 1The muscles of the anterior thigh. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas The lumbar plexus, femoral nerve and muscles of the posterior abdominal wall. The lumbar plexus, femoral nerve and muscles of the posterior abdominal wall. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More In gratitude to our body donorsLearn more In gratitude to our body donors We are deeply grateful to the individuals who chose to donate their bodies for the advancement of medical education. Their generosity makes these images possible and provides students and healthcare professionals with an invaluable opportunity to study human anatomy. We recognise the profound contribution made by each donor and their families, and we use these images with the dignity and respect their gift deserves. Acknowledge Frequent questions What is the iliopsoas muscle? The iliopsoas is a key muscle group in the anterior compartment of the thigh, consisting of the psoas major and iliacus muscles. These muscles work together to facilitate hip flexion. What are the attachments of the iliopsoas? The psoas major originates from the lumbar vertebrae, while the iliacus arises from the iliac fossa of the pelvis. Both muscles insert onto the lesser trochanter of the femur, forming a common tendon. What actions does the iliopsoas perform? The primary action of the iliopsoas is to flex the thigh at the hip joint. This function is crucial for various movements, including walking and running. What is the innervation of the iliopsoas? The psoas major is innervated by the anterior rami of L1 to L3, whereas the iliacus is innervated by the femoral nerve. This dual innervation is essential for coordinated muscle function. What is the blood supply to the iliopsoas? The iliopsoas receives its blood supply primarily from the iliolumbar branch of the internal iliac artery, alongside contributions from the obturator and femoral arteries. This vascularisation supports its metabolic needs during activity. Rate This Article