What does the term iliopsoas refer to?

The term iliopsoas refers to a combination of two hip flexor muscles: the iliacus and the psoas major. Together, these muscles play a crucial role in hip flexion, which is essential for activities such as walking, running, and sitting. The iliacus originates from the iliac fossa of the pelvis, while the psoas major originates from the lumbar vertebrae. Their convergence and shared tendon allow them to work synergistically to flex the hip joint and provide stability to the lumbar spine during movement. This anatomical and functional connection is why the answer correctly identifies the iliopsoas as the combination of these two specific muscles rather than a singular muscle or a group associated with knee movements.