As every Sweet and Sour Soup connoisseur knows, the Chinese zodiac assigns to each year the name of an animal (rat, pig, etc.). If there were a Runner’s Zodiac, I would have to declare 2000 the Year of the Hamstring.
I make this proclamation only in part as a result of the stunning outcome of the Olympic Trials Men’s 200-meter final last month. More notable to me is the extraordinary number of runners I have seen over the past half year with hamstring injuries; the total is probably as many as I have treated over the past three years! A good time, then, to update and combine some previous columns on this topic that appeared a few years ago.
The hamstring muscles (there are 3, located in the back of the thigh) can be injured in one of two ways. Sprinters such as Michael Johnson and Maurice Green typically suffer traumatic, rather severe muscle strains that we commonly call tears, or “pulls.” (As in “He pulled it!” – generally preceded with “Uh-oh!”) As anyone who watched that 200 final could guess, the onset of the injury is sudden, unexpected, and invariably quite painful. An understanding of the nature of this injury helps explain why this is the case.
Muscle strains are classified by degrees of severity. A Grade I strain, for example, signifies minimal damage and disruption to the muscle fibers. To the naked eye there may appear to be no injury, but a microscopic examination reveals small, intermittent tears of individual fibers. There is little if any bleeding or swelling and recovery time is generally a week or two.
A Grade II tear is more substantial and would be visible without microscopic assistance. There is probable bleeding as well as a result of small blood vessel (capillaries) disruption, and the area may become swollen and tender as the body begins the repair process. The bulk of the muscle, however, remains intact, which helps accelerate the healing process. Recovery time averages 2-4 weeks.
The worst situation, and the one experienced most often by sprinters, is a Grade III, or complete, tear. In this case, there is a complete separation of a large number of fibers within the muscle belly, leading to a serious amount of bleeding and swelling. Within a day or two, these fluids will appear as a large ecchymotic (black and blue) area beneath the skin, looking much like a bad bruise. In the case of hamstring pulls, it is rare that a single muscle is completely torn in half, though it does happen on occasion. Most often it is just a significant portion of the muscle, but enough to render the muscle virtually unusable. Recovery can be 3-8 weeks in length and is often an incomplete repair that leads to chronic problems.
The good news for distance runners: most of their hamstring strains fall within the first two grades. The bad news: because distance running-related strains are caused by overuse or repetitive stress – rather than single-episode trauma – they frequently become chronic, recurrent, and very often extremely difficult to treat. Consequently, we would do best to focus our energies on prevention of the injury in the first place.
Hamstring injuries in the distance runner may often be secondary to various muscle imbalances in the lower extremities, but most problems occur as a result of training errors. Speedwork and hills are two of the prime offenders, but not inherently so. It is the manner in which runners attempt to increase their speed on the track or hills that causes the injury; namely, it is the tendency to overstride that leads to trouble. You probably don’t need me to draw you a picture to understand the connection between a forced lengthening of one’s natural stride and eventual fatigue failure of the hamstring muscle. Runners in search of a faster pace would be better served by increasing their cadence, or leg turnover.
Keep this in mind during your next “quality” workout and you will go a long way toward avoiding an injury that – trust me – you do not want to sustain.