A cyclist visited my office last week to seek treatment for her back pain. Like many of us inspired by the Tour de France, she had been stepping up her workouts recently. This year she was feeling good going into the racing season — until her hip, back and leg became painful.

The patient was feeling particularly disappointed about her injury because this would be the first full season back for her since she had a child. She got checked out and was told that she had sciatica. A course of physical therapy helped a little but it didn’t last. She came to me hoping that I could inject her, or at least order an MRI to see if she had a bulging disc.

After a thorough examination, I found that she didn’t have sciatica at all. Instead she had one of the most confusing chameleons of the sports medicine world: piriformis syndrome.

The piriformis is a small, triangular-shaped muscle in the hip. It is primarily responsible for controlling the rotation of the hip while we walk or pedal. Because of its location, pain in the piriformis can feel like it is coming from the low back, the sacrum, or even the hip joint itself. Piriformis issues are easily mistaken for other, more common back injuries.

Doctors estimate that almost 1 in 10 cases of back pain actually come from the piriformis. This patient’s experience is not uncommon. Often, patients suffering from piriformis syndrome have been through multiple treatment approaches and sometimes have even had procedures performed on them without relief.

Cyclists and runners are especially prone to piriformis syndrome. Because the piriformis controls the rotation of the hip, it is called upon to work hard with each stride and each pedal stroke. Shoes with poor support and especially core weakness can overtax the piriformis, causing it to become painful and eventually dysfunctional.

Time trial bikes, with their aggressive seat angles and aero handlebar positions, are notorious for placing stress on the piriformis. Seats that are ill-fitting or just worn out from miles on the road can also be a factor. A good early stop for cyclists and triathletes with hip or back pain is to a FIST certified bike fitter. I’ve seen elite cyclists who were blown away when they learned that their rig has fit flaws. For the rest of us civilians, this is a no-brainer.

Because of its negative impact on core strength, pregnancy is a big setup for piriformis syndrome. Most athletes don’t feel the effects until months or even years later. When their training intensity increases, typically so do their symptoms.

This process can quickly escalate. In some cases, even walking becomes painful. I have seen patients forced to rely on crutches because of their piriformis syndrome.

In these extreme cases, even gentle physical therapy can be excruciating. Pool therapy can be a good way to help support the athlete’s body weight while allowing her to focus gentle strengthening on the piriformis.

Soon, they are ready to begin a series of stretching and strengthening exercises that form the core of treatment for piriformis syndrome.

Foam rolling, using a tennis or lacrosse ball to massage the piriformis, and strengthening the core are all great ways to get a jump on treating moderate piriformis syndrome at home. More painful cases sometimes need trigger point injections or dry kneading treatments.

However, the bottom line for the piriformis is clear. Though it is a small muscle in an out-of-the-way place, for athletes wanting to get the most out of their training, the piriformis needs to be powerful.

Dr. James Glazer is a sports medicine physician for Coastal Orthopedics and Sports Medicine in Freeport. He serves as a consultant for the U.S. ski team.