Hip Flexor Strain

A hip flexor strain is an injury that results from overstretching or tearing of the hip flexor muscles. These are the muscles responsible for hip flexion movements (pulling the thigh up towards the chest). They are also responsible for a hip extension movement, which is pushing your thigh behind you.

The featured photo above illustrates a hip flexor stretch, which consists of simultaneous flexion and extension movements. In the photo, the woman is flexing her hip with the left foot and extending it with her right.

Hip flexor strains can vary widely in terms of severity. They can range from a mild overstretching of the muscle (called a pulled muscle) to complete hip flexor tears. The latter may even include some bone damage.

The most common symptom of a hip flexor strain is sudden intense pain in the hip or pelvic area. You may also experience other symptoms including muscle spasms in the upper leg area, soreness in the area and others.

Treatment of most sprains requires resting the injured muscles, applying ice and taking pain relief medication.

Which Are The Muscles Responsible For Hip Flexion?

There are various muscles that are responsible for this movement, but the primary ones are:

• The iliacus and psoas, referred to collectively as the illopsoas muscles and located in the lower lumbar spinal region. These extend through the pelvis and end in the femur or thigh bone;
• The rectus femoris muscle, which is one of the quadriceps group of muscles at the front of the upper thigh.

A hip flexor strain occurs when any of these muscles is overused and then overstretches or tears as a result.

Causes & Risk Factors

Generally, hip flexor strains are caused by any activity that requires repetitive hip flexion or extension movements. They can also result from tight or under developed hip flexor muscles (those listed above).

The activities that increase the risk of hip flexor strain injuries include (but are not limited to) the following:

• Cycling, which requires repetitive high leg lifts (hip flexion);
• Dancing and martial arts, which also require frequent high leg lifts;
• Step aerobics, kicking a football and playing soccer.

Symptoms

If you have a hip flexor strain, you are likley to experience the following symptoms:

• A sudden intense hip pain, as well as pain in the pelvic area;
• Tenderness and soreness in your upper leg;
• Reduced strength in the anterior (front) groin area. As a result, you may lose some or most of the range of motion for hip flexion and extension movements;
• You may also experience upper leg muscle spasms;
• Swelling and bruising (contusions) of the upper leg may also be present;
• Your upper leg may also feel tight or still after you have sat or laid down for a while. It can also feel this way or after awakening from sleep.

This injury is closely associated with sporting activity. As a result, if you think you have experienced a hip flexor strain, consult a sports medicine health care professional.

Treatment

The good news about hip flexor strains is that the overwhelming majority of them are treatable using conservative non invasive approaches. Surgery is rarely required.

Non Invasive Treatment

Most grade I or II hip flexor strains (involving overstretching or partial muscle/tendon tearing) are treatrable at home. Your doctor may recommend:

• Resting the hip flexor muscles for a while. You do this by avoiding activities (such as those listed above) that involve hip flexion or extension;
• Wearing compression shorts or a groin wrap can ease the pressure on the hip flexors from daily activities like walking. This will in turn help promote healing;
• Applying ice or a cold compress to the painful area to ease the pain and reduce swelling. Do this for 2-3 days after the injury occurs, or until the pain and swelling have eased;
• Once the pain and swelling have receded, switch to using heat therapy to increase blood flow to the injured muscles. You can apply a hot compress or, alternatively, try warm showers or baths;
• If the pain persists, consider using pain relief medication like acetaminophen or Tylenol. For control of both pain and inflammation, consider anti inflammatory medications like ibuprofen, advil or motrin.
• As your recovery proceeds, your doctor may also suggest enrolment in a physical therapy program. This will help you to stretch and strengthen your hip flexor muscles. This will reduce the risk of re-injury after you have resumed your regular activities.

Surgery

In cases of a grade III strain (complete severing of muscles or tendons) surgery may be necessary to correct the problem. This may especially be the case if bone damage has occurred.

Your doctor will be able to go through the precise surgical options. Fortunately, the cases in which surgery is required to treat a hip flexor strain are relatively rare.