When it comes to foot-pounding exercise, there can be too much of a good thing. Over-training in sports or fitness can lead to tiny stress fractures in the bones of the legs and the feet. But some stress fractures are caused by medical conditions that weaken bones, leaving them vulnerable to fracture even with normal use.

At Yale Medicine, we have orthopaedists, physical therapists and athletic trainers working together to treat the whole individual, not just the fracture.

Citing the common example of a weekend runner who decides to train for a marathon, Peter Jokl, MD, a Yale Medicine orthopedic surgeon, says stress fractures typically arise in athletes who are enthusiastic about taking on a challenge—and who push themselves too hard, too fast.

Another example, he says, is a tennis player who tested a new kind of ball with more than 10,000 swings of the racket. “If a bone isn’t given time to accommodate the additional stress of intense training, it is likely to crack,” he says.

Bones, in particular, benefit from gradual escalation in training, Dr. Jokl says. While muscles enlarge quickly when pushed and tendons gain strength rapidly, “The metabolic process of  strengthening the bones takes longer,” he says.

The vast majority of stress fractures affect the lower extremities (femur, tibia, fibula and feet), but any bone can sustain one, says Dr. Jokl. He has treated rowers with stress fractures in their ribs, from pulling the oars through water rapidly. A baseball pitcher can get a stress fracture in his shoulder, a tennis player in the elbow. If a bone is part of a repeated, strenuous athletic motion or physical activity, it could be at risk for a stress fracture.

There are several medical conditions that, indirectly, make stress fractures more likely. Osteoporosis, or loss of bone density and flexibility, is the most common of those, but there are other metabolic conditions that increase risks. Also, cancer that begins in, or has spread to, the skeletal system can weaken bones to the point where a stress fracture can result from normal activity, says Dr. Jokl. 

When Yale University first admitted women in the 1960s, the orthopaedic team saw a sudden rash of stress fractures in female athletes, because the rigorous training that college sports required was new to them.

The sports landscape has changed since then but, Dr. Jokl says, another difference now commonly presents itself. “Today, what we see is the female athlete who has trained so hard that her menstrual periods have stopped,” he explains. “The resulting drop in estrogen levels alters the body’s calcium metabolism, making such women more prone to a stress fracture.”

Also, osteoporosis raises risk for stress fracture. Far more women than men get osteoporosis so that, too, makes women more vulnerable.

Most stress fractures begin as a dull ache and, when ignored, become very painful. Dr. Jokl often hears comments from runners who come in and say things such as, “It was painful, but I kept running.” The additional pounding irritates and exacerbates the stress fracture, causing it to grow larger. 

Stress fractures should be addressed right away. If they aren't treated, the whole bone could be fractured all the way through.

A stress fracture can be tricky to diagnose. “Early on, the X-rays are nearly always negative because the crack is tiny and there’s no displacement of bone,” says Dr. Jokl. He says a sports medicine specialist will suspect a stress fracture based on a patient’s history and description of his or her symptoms. “MRI (magnetic resonance imaging) can be helpful” in confirming its presence and location, he says, noting that Yale Medicine also has highly sophisticated imaging technology that can detect even very tiny fractures.

The most effective treatment for a stress fracture is rest that allows the crack to heal. This advice is not always well received by patients who are competitive and committed athletes, says Dr. Jokl. This, he says, is a reason to seek treatment from an established sports medicine program such as the one at Yale Medicine, where experienced professionals can offer guidance and support to help athletes recover. 

“If a bone isn’t allowed to heal properly, the danger is that the whole bone will break,” Dr. Jokl says, adding that specific bones (in particular, the hip) are especially vulnerable. “Our approach is to get people quickly diagnosed and treated so they don’t lose conditioning. Part of our treatment regimen is helping athletes to find other ways to maintain fitness.” 

For example, he says, a runner with a stress fracture of the tibia can wear a buoyancy device to train in a swimming pool, maintaining heart and lung fitness without putting any weight on the affected bone.

Yale Medicine Orthopedics & Rehabilitation is staffed by highly specialized physicians, physical therapists and athletic trainers who are experts in their fields. “We have orthopaedic physicians who specialize in treating women athletes,” says Dr. Jokl. “We have imaging equipment that is sensitive and sophisticated enough that we can make diagnoses that might be missed by others.”

Another advantage, Dr. Jokl says, is that Yale Medicine offers access to a wide array of services for people with complex medical problems that affect bone density, including eating disorders, metabolic conditions and cancer, among others. “If we see an athlete with a stress fracture who also has an eating disorder,” he says, “we can provide the connection to the other resources he or she needs, including nutritionists and psychologists.” 

With an emphasis on collaborative, multidisciplinary care, Yale Medicine is able to treat the whole person—not just the stress fracture.