I am a yoga instructor with a very painful hip. I can’t figure it out because my joints are very loose. But every time I flex my hip past 90-degrees or try to cross my legs, I get a very sharp pain deep in my hip. What could be causing this?

Hip pain with limitations on full hip motion in an active adult requires special attention — especially if you are in your 20s or 30s. Early diagnosis and treatment is imperative to avoid degenerative changes in the hip joint later in life. There are many possible causes of this type of hip pain. Given your description, one of the most likely would be femoroacetabular impingement (FAI).

Femoroacetabular impingement (FAI) describes a condition where the top of the femur (thigh bone) pinches the rim of the hip socket. The area that gets compressed is referred to as the acetabular rim. This type of impingement occurs most often when the hip is flexed and internally rotated.

For a long time, it was believed that FAI only occurred in people with some kind of abnormal anatomy of the hip. There was either a backward tilted angle of the hip socket called retroversion, a larger socket than the ball (head of the femur) inside the socket, or flattening of the femoral head. One type of abnormal shape of the hip was labeled a pistol grip because of the resemblance to the grip of a handgun.

More recent studies have shown it’s possible to develop FAI even when the hip structure and anatomy are essentially normal. But, in general, more people with acetabular retroversion end up with hip pain and problems leading to degenerative hip osteoarthritis than any others.

To get to the bottom of the cause of hip pain, a thorough history and examination are required. An orthopedic surgeon or sports medicine physician is the best one to see. The physician will look at your foot position, leg angles, leg length differences from one side to the other, hip motion, and muscle strength. Gait (walking) patterns will be evaluated.

Special tests such as the impingement test are done to identify the presence of an underlying FAI as the cause of the painful symptoms and restricted motion. X-rays, CT scans and/or MRIs may be used to confirm the diagnosis. The results of all of these tests are important pieces of information when deciding on the best treatment approach.

With early diagnosis and treatment of young, active patients with FAI the problem can be managed by conservative measures. Surgery may be needed to restore as normal hip anatomy as possible. But before jumping to any conclusions, make an appointment and see a specialist to find out for sure what might be causing the problem. If you’ve had this for a while and it hasn’t gone away (even with your yoga practice), don’t wait any longer.