Hip Flexor Injuries and Prevention Strategies

Hip flexor (rectus femoris)  injuries occur more frequently in running, sprinting and kicking sports. Soccer players in particular are prone to hip flexor injuries.   Chronic hip flexor, rectus femoris, and groin pain can also be seen in athletes, gymnasts and dancers. Hip flexor injuries involve one of two muscle groups: The Rectus Femoris which is part of the quadriceps or the Psoas muscle which is a large hip flexor.

Acute injuries generally result in tears of the Rectus Femoris hip flexor in soccer players, American football players, and runners. Chronic hip flexor pain is generally felt to be due to the Psoas tendon.

The rectus femoris is one of your quadriceps muscles. It is unique when compared to the other muscles in the quadriceps group because if crosses both the hip joint and the knee joint. When muscles cross two joints they are more prone to injury. With quick, violent kicks or sprints, the upper portion of the rectus femoris muscle is commonly injured or torn. In adults the injury almost always occurs in the rectus muscle just below the hip joint. In adolescents, because they are still growing, they usually injure their rectus femoris where it attaches to the pelvis. Some players recall feeling or hearing a pop or a tear. Most simply notice pain when they kick the ball or lunge forward quickly. Then the pain builds or worsens and they point to the top of their thigh, near the hip joint as the source of their pain.

Hip Flexor and Rectus Femoris Injury

Most injuries to the rectus femoris in adults does not result in a complete muscle rupture, although complete hip flexor tears can happen. Most injuries are partial tears or strains. Most children with hip flexor injuries actually pull a small piece of bone off of the pelvis. Both of these hip flexor injury patterns usually heal quite well and are managed with activity modification, therapy and without surgery.

Treatment and Prevention of Hip Flexor Injury

The treatment of nearly all hip flexor acute injuries involving the rectus femoris is non-surgical. Rehabilitation for stretching can begin within a few days. Crutches might be needed if the pain is severe. Stationary cycling with low resistance is a good exercise for those who just suffered a hip flexor injury.  Avoiding anti-inflammatories for the first few days is a good idea.  Anti-inflammatories can shut down the early healing process.
Recovery from a rectus femoris hip flexor injury can take 4-6 weeks in most cases before an athlete can return to the playing field. If a player with a rectus femoris injury returns too early they risk a recurrent injury or injuring other structures in the leg if their strength and coordination are not normal and the leg is not properly rehabilitated.

Until very recently, and quite surprisingly, there has been very little scientific literature studying the effects of simple hip flexor strengthening regimens to potentially prevent injuries of the rectus femoris. A group out of Copenhagen recently studied a number of athletes and found that their hip flexor strength improved by 17% in only 6 weeks when working with an elastic band tied to the lower end of their thigh while they flexed their hip forward in the standing position with a forward lean. The authors postulate that this might be a simple useful tool to minimize the risk of acute rectus femoris hip flexor injuries.

Chronic hip flexor or groin pain often includes the psoas tendon, tensor fascia lata as well as the rectus femoris. Significant hip flexor weakness is very often found in patients with chronic groin pain. No one knows if the weakness lead to the chronic hip pain or the chronic hip pain led to weakness.  Issues with the psoas tendon can also coexist quite frequently in patients found to have FAI.

What does all this mean? This means that patients potentially facing FAI surgery would benefit from this simple hip flexor strengthening program before and after surgery. In addition, those with chronic long term groin or hip pain may be able to DIY their recovery by performing this elastic band strengthening exercise after being properly diagnosed by a medical professional.

Recovery From A Hip Flexor-Rectus Femoris injury

Most everyone will be able to return to play within 6 weeks following an acute or recent rectus femoris injury. For those of you with chronic long term pain, the  strengthening program noted above might be the appropriate treatment and also aid those athletes in returning to their chosen sport.

If you’ve been reading this blog you starting to see a trend in the science of muscle and tendon injuries in athletes.  Athletes who are pushing the envelope when training are walking a fine line between performance and mal-adaption or injury.  We know that hamstring injuries are common and we’ve talked about the risk of a recurrent injury if you return to play to soon. We know that hamstring strengthening can decrease the risk of ACL injuries.  The hip flexors are part of the anterior chain and the hamstrings are part of the posterior chain.  It is becoming clear that proper strengthening and balancing those efforts is key avoiding injury.. and re-injury after rehabilitation.