Leg > Shin Splints

What are Shin Splints?

The term shin splints (medial tibial stress syndrome) refers to pain around your shinbone related to tearing and/or inflammation of muscles or tendons attaching the shinbone (tibia) on the side facing the opposite leg. The problem occurs about one-third of the way up to the knee from the foot. The lower leg muscles pull on a layer of tissue (periosteum) that covers your shinbone. Constant strain on the periosteum inflames the muscles' attachments to the shinbone, which causes pain. Cracks in the shinbone, known as stress fractures, which most commonly occur in runners, may occur in the same location. A separate, less common injury known as chronic exertional compartment syndrome may cause pain in the muscle groups on the outside (little toe side) of the shin bone.

Shin splints are commonly caused by overuse of your lower leg muscles during endurance activities like running. Repeated use of your calf muscles may strain the attachments to the shinbone. Running on strained lower leg muscles may pull the attachments too far and further tear muscles or tendons. Depending on whether you run on your heels or your toes, on hilly or flat surfaces, and the nature of your leg structure, running may cause a strength imbalance between the back and front of your lower leg muscles. The back of your muscles may develop faster than the front when running, which allows the back of your calf muscles to pull harder than the front can withstand, and may predispose you to shin splints and other conditions. Abrupt changes in your activity level also put you at risk for developing shin splints. Switching from running two miles a day to five miles a day can put too much strain on the muscle attachments to your shinbone. Many people develop shin splints when starting a new activity or adding a new exercise to a training regimen. For example, a fit athlete who has been running 30 miles a week may suffer shin splints by adding hills or sprinting to a daily workout. If new exercises use the lower leg muscles in a different way, shin splints may occur. Abnormal biomechanics, poorly fitting footwear, or uneven surfaces can also cause shin splints. If your foot tilts oddly in any direction, due to the shape of your foot or ankle, the fit of your shoe, or the type of surface on which you are running, your lower leg muscles and bones may be injured when absorbing the energy of the strains and impacts.

It is important for your physician to evaluate your leg when you have pain around your shinbone because the symptoms of shin splints are similar to other, more dangerous lower leg injuries, such as stress fractures. Stress fractures are often thought to be incomplete fractures, meaning that it is an internal crack within the bone, without separation between the fragments, but this is often not true. Stress fractures are literally those that derive from an excess of activity (too much stress) relative to the tolerance of reasonably healthy bone. Stress fractures in your shinbone may be more likely to fracture completely during activities that normally would not cause injury. If left untreated, shin splints usually continue to hinder your athletic performance and can bother you during daily activities. Non-surgical treatment is usually effective to alleviate shin splints; however, non-detection in the face of continuing activity can be dangerous.

Though many people with mild or moderate shin splints feel they can treat themselves at home, you should almost always have your lower leg evaluated by a physician, who can check for other problems, such as stress fractures, and decide on a specific treatment program for your lower leg. There usually are three parts to an orthopedic evaluation: medical history, a physical examination, and tests that your physician may order.

Your physician likely will ask about your activities, which may have caused the shin splints. You will be asked when the soreness or pain began, and if there were any recent changes in your activities. If you have had any prior lower leg injuries, your physician will ask about the treatments you have tried in the past. You will also be asked how long the shin splints took to become bothersome, and whether you have had to stop playing sports or participating in activities because of your shinbone pain. You may also be asked about your physical and athletic goals – information that will help decide what treatment might be best for you in achieving those goals.

Your physician can usually make an initial diagnosis of shin splints by pressing on the muscles around your shinbone to pinpoint your pain. Patients rarely have a limp due to shin splints, and muscles tend to function normally. When you have shin splints, pain is usually more intense as your physician presses the soft tissue right next to your shinbone. If direct pressure to your shinbone causes the most pain, it could be a sign that you have small fractures in the shinbone called stress fractures. The physical examination should include evaluations of comparitive strength, flexibility, swelling, and tenderness between the afflicted and unafflicted sides.

TESTS

Should your physician require a closer look, these imaging tests may be conducted:

   X-rays taken from different angles may be used to rule out stress fractures in your shinbone. However, X-rays may fail to reveal new stress fractures; it usually takes weeks or months for stress fractures to show up on X-rays.

   A bone scan, performed by a radiologist, may be taken to detect stress fractures. An injection of an isotope (a radioactive bone-seeking heavy metal) is followed several hours later by a scan of the bone.

   MRI (magnetic resonance imaging) is the other radiographic test used to detect stress fractures. It has a very high success rate in revealing bone as well as tendon, muscle and ligaments in three dimensions, and is usually the procedure of choice.