The sartorius supports the more powerful iliopsoas and rectus femoris in accomplishing hip flexion. This long, narrow muscle arises from the front of your hipbone, crosses your front thigh and inner knee and inserts at the top of your shinbone. The unique position of the sartorius enables it to support other leg motions, including knee extension, leg rotation and outward thigh movement. Sartorius strains, which commonly occur in runners and hurdlers, usually occur where the muscle arises at the hipbone. Pain and leg weakness are common symptoms. As with the other hip flexors, stretching and strengthening exercises serve as good preventive measures.
The wisdom that Sahrmann shares in her book Diagnosis and Treatment of Movement Impairment Syndromes explains many of the injury riddles of the Strength and Conditioning field, particularly the “hip flexor pull” or “quad pull.” The key to understanding the motion of hip flexion comes from looking at the anatomical leverages of the different muscles involved. There are five muscles that are capable of assisting in hip flexion:
Dean Somerset, CSCS, a personal trainer and post-rehab specialist in Edmonton, Alberta, is owner of Somerset Fitness Ltd. He has a degree in kinesiology from the University of Alberta and is certified by the Canadian Society for Exercise Physiology and the National Strength and Conditioning Association. He’s written articles for The PTDC as well as T-Nation and Bodybuilding.com, and contributed to Men’s Health, Women’s Health, Shape, Men’s Fitness, and many other magazines and websites. You can contact him at his website or Facebook , and check out his unique approach to training on his YouTube channel.
Iliopsoas muscle and tendon strains may occur with activities that require repetitive hip flexion, such as hurdling, uphill running and playing soccer. Deep hip pain is the primary symptom. Hip flexor stretching and strengthening exercises reduce the likelihood of iliopsoas strains. Weighted or unweighted leg raises from a standing, sitting or lying position strengthen the iliopsoas and other hip flexors.
The primary hip flexors are the rectus femoris, iliacus, psoas, iliocapsularis, and sartorius muscles. The rectus femoris muscle has two distinct origins proximally: the direct head and the reflected head. They originate at the AIIS and the anterior acetabular rim (in close proximity to the anterior hip capsule), respectively. The tendinous fibers of the rectus femoris coalesce distally and become confluent with the other quadriceps musculature in the thigh. The quadriceps consists of four distinct muscles: 1) the vastus intermedius; 2) the vastus lateralis; 3) the vastus medialis; and 4) the rectus femoris. The rectus femoris is the only quadriceps muscle that traverses both the hip and the knee joint. The rectus femoris is a powerful hip flexor, but it is largely dependent on the position of the knee and hip to assert its influence. It is most powerful when the knee is flexed, whereas significant power is lost when the knee is extended. The rectus femoris is innervated by the femoral nerve (i.e., the posterior division of L2 to L4).
Grade II (moderate): A larger tear in your muscle that makes it difficult to move and causes a moderate amount of pain, especially when you move the affected muscle, swelling, and tenderness. You may have 5 percent to 50 percent loss of function and you may be limping. You can't go back to sporting activities until the tear is completely healed. These injuries can take anywhere from a couple weeks to a few months to heal, depending on how bad they are.
Lucky for us, there are tons of different ways to stretch hip flexors. We’ve put together a broad selection of some of the most popular tight hip flexor stretches below. Some of these stretches may work better for you than others, and there’s also many more hip flexor stretches you can try beyond these. So, experiment with all different kinds of stretches and decide which ones are best for your body.

How to: Lie on your back with your right knee bent and foot flat on the floor (a). Extend your left leg up to the ceiling and wrap a strap around the sole of your left foot (b). While holding both ends with your left hand, extend your right arm directly out to the side in order to anchor yourself (c). Slowly let the left leg fall toward the left while keeping your right side grounded. Hold for six to eight breaths, then repeat on the opposite side.
×