The rectus femoris is one of the quadriceps muscles of the thigh. It crosses two joints – the hip and knee. It is commonly injured as the tendon at the front of the hip or in the muscle belly of the thigh. This injury is what many people refer to as a “hip flexor strain.” It is a common injury in sports such as soccer and football. Usually it involves a forceful movement such as immediately starting to sprint or forcefully kicking a ball, especially when the athlete’s foot strikes another player while trying to kick.
These injuries are almost always acute ones. The football player or soccer player will notice immediately that an injury has occurred. With a rectus femoris tendon strain, the athlete will localize the pain to the front of the hip. A sports medicine physician examining the player might notice a defect in this area if a full tear is present, but a full tear is unusual. More frequently, the physician will notice pain or weakness with resisted hip flexion or resisted knee extension. He or she might order x-rays to determine if the athlete pulled a small piece of bone off one of the bones in the hip, as you can occasionally see in young athletes who are not done growing. In high-level athletes especially, the physician might order an MRI of the hip. The MRI will help to confirm which tendon is involved. It can also give a better idea of the extent of injury and how long it might take the athlete to recover and return to sports.
As with most tendon and muscle strains, treatment is almost always nonoperative. Rest from the offending sport and ice to the area can be helpful. As the pain and swelling improve, cardiovascular exercise that does not stress the rectus, such as a stationary bike, can be helpful. As the athlete continues to improve, he or she will start jogging before progressing to a sport-specific rehabilitation program. Working with a sports physical therapist can help tremendously. Return to sports is likely, but it can be difficult to estimate the length of time prior to full recovery. Occasionally the athlete will get back in 1 to 4 weeks, but occasionally it can take 6 to 8 weeks or more.