The term, overuse, is certainly not unfamiliar to our jogging population. Most of the authoritative texts and articles dealing with running problems have often alluded to the so-called "overuse syndrome" and its debilitating effects upon the body. In short, the term implies an apparent irregularity in either the training or actual race performance. Simply stated, the athlete is running too much, too fast, or both. A frequent use of this term is in reference to the marathoner who, during the training period, suddenly increases the training mileage in order to stay on an acceptable schedule. When this athlete begins to experience discomfort in his or her lower extremities either during or after running, we categorize the condition as an overuse syndrome.
Although the term has an interesting sound and allows those of us in the healthcare profession to comfortably categorize running ailments, it is often misleading and, at best, non-specific. It is my feeling that a basic problem exists in either the limb function or style of running which is the culprit and not the distance or pace involved. Granted, the speed and mileage increase may aggravate an existing problem enough so that it becomes apparent clinically. However, the underlying dysfunction or defect in style is present during everyday walking, short distance running, and/or marathon training. By accepting the frequent use of the term "overuse", we perpetuate this misconception as well as hinder our management of the problem itself.
The most common ailments, which seem involved in these cases are the various knee conditions and lower leg pain or shin splints. It is interesting to note that both of these areas usually have an underlying excessive inrolling or pronation component, which leads to limb dysfunction and pain. When we focus in on this causative factor, our treatment plan is usually more successful as opposed to using distance and pace as the primary means of management. Again, I emphasize the fact that the individual, who excessively pronates, does so with each and every step. Thus, the disparity exists prior to the first step of the run. Whether or not it becomes evident as an interrupting force may well depend upon the pace and distance performed. But you can be sure that the basic problem is there and sooner or later, with continued running, it will surface.
I am often asked by my jogging friends why it is that many of the running related problems were non-existent until a certain mileage range or level of workout was reached. Then, all of a sudden, the efficient and pain-free running machinery seemed to rapidly deteriorate. My answer has to do basically with the cumulative effects of impact stress incurred during the gait cycle. Allow me to explain this concept in as simple a manner as possible. With each step of regular walking as the heel contacts the ground, a personís approximate body weight is carried though the foot and into the limb above. A 200-pound man will have about 200 pounds of force passing through his weight-supporting limb with each step.
The runner is in a different ballpark. Due to the airborne phase of the running cycle, in addition to body pace and forward momentum, it is estimated that from three to eight times oneís body weight passes through the supporting limb. A weight force of from 600 to 1600 pounds is quite another subject, particularly in the presence of a functional problem. Consider the case where a runner excessively pronates due to a certain type of structural abnormality. In this situation the large weight force, which is supposed to be properly absorbed and distributed upon foot strike is abnormally transferred up the limb. Also keep in mind that in an hour of average running, a foot may strike the ground some 2000 times. With repetitive trauma such as this, it is but a matter of time before the body reacts to the cumulative strain. The body is capable of handling only so much of the so-called abuse before discomfort becomes an evident factor.
The human body is indeed an amazing piece of machinery. And yet we, as runners, must not be neglectful of its physical limitations. In the presence of abnormal function during gait, it is understandable how this highly tuned piece of machinery can at some point light up the alarm button. The implications of the term, "overuse", do not do justice to the nature of the problem. Instead, the focus of interest becomes treating the label and overlooking the cause. Once we recognize the importance of re-establishing proper mechanics during the gait cycle, we will be well on our way toward improving our running performance.