Hip flexion describes the bending motion that brings your thigh toward your chest. The muscles that accomplish this movement are collectively known as hip flexors. These muscles are among the most active in your body, initiating each step you take. Running, jumping, kicking and cycling are among the many activities that rely on strong hip flexion.
The term iliopsoas refers to the iliacus and psoas muscles, which are grouped together because they function collaboratively and share a common tendon. The psoas originates from your lower spine, and the iliacus arises from the inside of your hipbone. The muscles come together as they cross through the pelvis and insert on the inner thighbone below the hip joint. The iliopsoas is the most powerful hip flexor.
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 rectus femoris is one of the quadriceps muscles. The rectus femoris arises from the front of your hipbone, runs through the middle region of the front thigh and attaches to the top of the kneecap. In addition to hip flexion, the rectus femoris straightens, or extends, your knee. This dual function increases the vulnerability to strain injuries. Stretching exercises to maintain flexibility and balanced training to equalize your quad and hamstring strength reduce the likelihood of rectus femoris strains.
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 pectineus is an accessory hip flexor. This short muscle originates from the front of the pelvis, crosses the hip joint and inserts near the top of the thighbone. In addition to hip flexion, the pectineus works with other muscles to move your thigh inward. The pectineus may be involved in groin strains, which occur commonly among players of sports that require rapid acceleration and position changes.
Tensor Fasciae Latae
The tensor fascia latae originates from the front of the hip and inserts into a long fibrous band called the iliotibial tract on the outside of the thigh. This muscle supports hip flexion, leg rotation and outward movement of the thigh. Tensor fasciae latae syndrome, also known as iliotibial band syndrome, is an inflammatory condition that most commonly develops in distance runners. Inflammation arises when the muscle and band repetitively rub against the outer head of the thighbone, frequently causing a painful snapping sensation in the hip. Treatment typically involves anti-inflammatory medication and hip-strengthening and range-of-motion exercises. Good running shoes can help prevent tensor fasciae latae syndrome by promoting proper hip, knee and ankle alignment.
- ExRx.net: Iliopsoas
- Sports Medicine; Anthony A. Schepsis, M.D. and Brian D. Busconi, M.D.
- Family Practice Notebook: Iliopsoas Strain
- ExRx.net: Hip Exercise Menu
- GetBodySmart: Rectus Femoris Muscle
- American Academy of Orthopaedic Surgeons: Muscle Strains in the Thigh
- GetBodySmart: Sartorius Muscle
- Radsource: Apophyseal Avulsion Injuries of the Pelvis
- ExRx.net: Pectineus
- ExRx.net: Tensor Fasciae Latae
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