Funny how things seem to go in streaks. Last year at this time, it seemed every runner in my office had an iliotibial band problem. This winter, the injury of choice seems to be stress fractures. A coincidence? Perhaps, but maybe not so much if you understand what a stress fracture actually is, what causes one, and why they may be more prevalent at this time of the year.
A stress fracture is a small, non-displaced crack or break in a bone caused by repeated application of minor force, rather than one large force. Clearly, this is your classic overuse injury which, as we’ve seen before, can usually be traced back to what we call “training error” — too much or too fast, too soon. Bone is living tissue, susceptible to the same breakdown from repeated trauma or stress as are muscles, tendons and ligaments. The bones most likely to be fractured in runners are the metatarsals and the lower tibia (shin), though the femur (thigh) and pelvis are not by any means immune. (True story: Several years ago, a runner in the Boston Marathon unknowingly sustained a stress fracture of his femur at about mile 3. He continued running, in some substantial pain, but as soon as he crossed the finish line and started walking, his bone completely separated and he collapsed. Doctors later surmised that his thigh muscles had acted as a splint, keeping the bone together, as long as he ran, but when they relaxed it allowed the two sections to come apart!)
While biomechanical discrepancies play a role in susceptibility to stress fractures (overpronators tend to break the 2nd and 3rd metatarsals, underpronators the 5th), experts generally agree that the primary cause is, quite simply, too much pounding when your not in good enough condition. Footwear can also play a role sometimes, especially if you go from a well-cushioned training shoe to a lightweight or racing flat.
How do you know if you have a stress fracture? Diagnosing this injury can be tricky, since the initial symptom is a gradual onset of low-level pain, not unlike what we experience with tendinitis. Since the pain is mild, most runners tend to (surprise!) try to ignore the discomfort and continue the activity. A stress fracture, though, will not go away, so continued running will aggravate the injury and the pain will get worse, becoming more intense, more constant and deeper. Pain usually ceases when the activity ends, but returns quickly when running is resumed. Downhill running may be especially painful and should be a cardinal warning sign.
Clinical examination will sometimes reveal swelling, but most often this is felt, not seen. The area is tender and direct pressure over the fracture site can be quite uncomfortable, especially when tapping the bone smartly with the fingertips. Application of therapeutic ultrasound over a stress fracture often elicits sharp pain, so if you are being treated for what is thought to be a muscle strain or tendinitis and you experience this reaction, be sure to tell your therapist. Pain from ultrasound is not normal!
X-rays unfortunately will not test positive for a stress fracture until about three weeks after the injury has been incurred. At that point, callous formation at the site will show up, indicating that healing of a fracture is taking place. A bone-scan, on the other hand, will usually be reliable early on in revealing a stress fracture.
Treatment of stress fractures is usually straight-forward and simple: REST! From running, that is, for 6-8 weeks depending on the location and severity of the fracture. Sometimes crutches or a cast are required, but most of the time you simply have to stop running. You cannot run through this, so you should focus on an alternative activity, such as biking, swimming and sometimes pool-running. Be sure your physician OKs the latter before trying this.
Now, back to “why so many this time of year?” This is only theory of course, but it seems logical when you think of all the runners who have essentially “geared down” for the winter after the summer and fall racing season and then pushed up the mileage too quickly in March to get ready for Boston, Ottawa, Mountain Goat, etc., in early spring. Or, think about the shorter distance specialists who spend December – March on the indoor track at Manley, with its non-banked, mostly-curved, somewhat-worn surface, wearing their lightweight racing shoes with little support or cushioning…..
Getting the picture?