On Dance Injuries: Leg Pain

July 6, 2011

Do your shins hurt??  Leg pain in dancers is pretty common. It is usually from one of three things: a shin splint, a stress fracture, or something called a compartment syndrome. They are all due to overuse, faulty technique, and hard floors. They are characteristically brought on by activity and relieved by rest. They often get worse if they are not treated, and one, the acute compartment syndrome, can be a medical emergency. Let’s look at them one by one.

First, the anatomy: The leg has two bones that run parallel from the knee to the ankle; a large one, the tibia on the medial side, and a small one, the fibula on the outside. Attached to these bones are all the muscles that run down into the foot and ankle, along with the blood vessels and nerves. The muscles are encased in a tight sheath called the fascia that is similar to the casing on a sausage or a bologna.

A shin splint is actually a strain of the attachment of a muscle to the bone where the muscle originates. It is characterized by localized pain and tenderness exactly at the site of attachment usually on the side of the tibia, not on the front. A very common one in dancers occurs where a small muscle that flexes the lesser toes, (i.e., toes 2–5) attaches to the back of the tibia (the flexor digitorum longus or FDL). It usually is caused by constantly grabbing the floor with the toes, by “rolling in” when you land, and by too much jumping on hard floors. It responds well to icing, reduced activities, physical therapy, and technique modification.

Another similar syndrome occurs further down on the tibia just above the inside of the ankle and is called the soleus syndrome. In extreme cases this may need to have its fascia released surgically. See figure.

Stress fractures
of the tibia in dancers usually occur along the anterior border (i.e., the front) of the tibia. They are caused by excessive jumping on hard floors and result in a localized, painful lump. If they have been there for any length of time, they will show on an X-ray. However, in the early phases (less that 3 weeks) they may not show on an X-ray but a bone scan will be positive.  They can be neglected or misdiagnosed, in which case they can eventually become “the dreaded black line” seen on an X-ray. These can take a very long time to heal and may require a drilling procedure.

The treatment of a stress fracture depends on how severe it is and how long it has been present. If it is mild and fresh, we usually treat the dancer with activity modification (i.e., no jumping or grand pliés) a removable boot, and a bone stimulator. If it is old, painful, and doesn’t look good on the X-ray, a more aggressive treatment plan is needed: walking boot, bone stimulator, and Partial Weight Bearing [PWB] with crutches until it is healed.

Unfortunately, the rule of thumb for healing is that it will take as long to heal as the dancer has been working with the pain—and this is sometimes months. The good news is that they usually do heal, especially with the new type bone stimulators.

There is a less serious condition called a stress reaction, which is an impending stress fracture that hasn’t actually occurred yet. The analogy we use is this: a stress fracture is similar to bending a paper clip until it breaks, whereas a stress reaction is when you are bending the paper clip but it hasn’t broken yet—but if you don’t stop the bending it will break. Obviously, stress reactions heal much faster than stress fractures. The symptoms in both cases are similar.

Compartment syndromes
of the leg occur when the muscles swell up within their tight fascias or sheaths surrounding the muscles and choke off their own blood supply. They are much more common in sports that require a sustained effort, like running or soccer, and are rare in dancers. That’s because dancers usually perform in bursts of energy for relatively brief periods of time—more analogous to football than soccer. The leg pain usually builds up with exercise and can be severe. In extreme cases following trauma, the lack of blood supply can actually cause the muscles to die (necrosis). The acute compartment syndrome is a medical emergency that requires surgery to release the tight fascia before necrosis occurs. It usually happens as the result of an injury such as a direct blow to the leg.

Compartment syndromes
are usually diagnosed by placing a needle into the muscles with local anesthesia, and measuring the pressures directly while exercising on a treadmill. Severe cases may need to have the tight fascia released.

The point of all of this is that, whatever the cause of leg or shin pain, if it hangs around for any length of time it should be accurately diagnosed. Then it can be properly treated and you can get back to what you love to do—simply dance.

William G. Hamilton, MD is an orthopedic surgeon in private practice in New York City. He is the orthopedic consultant for the New York City Ballet, American Ballet Theatre, the School of American Ballet, and the JKO School of Ballet at ABT. He specializes in foot and ankle injuries in dancers and athletes. He is past president of the American Orthopedic Foot and Ankle Society.