Hip Flexor Anatomy – Main overview

Hip Flexor Information


The hip flexor is a crucial part of human functioning in everyday life. From basic activities like walking, standing up and sitting down, to physically demanding activities like sports and weight training, the hip flexor is involved more than you might know.

What does the Hip Flexor do?

The hip flexor has both major and minor functions, it is able to fulfill different roles because it is composed of several muscles, the largest ones are discussed below. The primary goal of the hip flexor is to facilitate flexion of the hip joint. In normal terms, this means that the hip flexor is used anytime the knee is lifted up, a step is taken, or a stair is climbed.   The hip flexor also has those smaller muscles whose purposes are mainly stabilization roles, so when you lift up your knee on an angle, these muscles provide the power needed in the lateral(horizontal) direction.

Where is the Hip Flexor?

Everyone knows all about the hamstring, the quad, the groin, but the hip flexor gets far less exposure, even though it is just as important as any other muscle in your body and is just as often at risk of an injury, most commonly a hip flexor strain. The hip flexor is a muscle group located towards the front of your leg/abdomen; it is composed of smaller, but sizeable muscles as shown in the picture. When looking at what the hip flexors do, we must examine the role that the Psoas and Iliacus play in movement; these are the two main muscles in the Iliopsoas, which is by far the largest and most important muscle group in the hip flexor.

The Psoas:

The Psoas muscle is actually divided into 2 distinct sub-muscles: Psoas major and Psoas minor. The Psoas major is the larger muscle that connects the pelvis to the lumbar region, as shown in the picture and is one of the major muscles at risk for a hip flexor injury. The Psoas minor on the other hand is a muscle located slightly in front of the Psoas major in the hip flexor muscle group; however, it is important to note that only about half of humans have this muscle! The minor muscle supports the same role that the Psoas major plays, which is to facilitate flexion of the hip joint.  If you have recurrent pain in the psoas area, you might want to read about hip flexor tendonitis.

The Iliacus:

The Iliacus is that small triangle shaped muscle shown in the picture, its role is to assist with movement, but mainly it functions by connecting the hip bone to the Psoas major.