Running injuries can be defined in numerous ways and their treatment suffers from the lack of a consistent set of defining parameters.
The scientific literature variously defines a running injury to have occurred when it is severe enough to reduce the volume of miles run and cause the runner to take a medication or see a health care professional. Others define a running injury as an incidence that hampers training for at least one week.
When the literature is examined to determine the incidence of running injuries (in studies of 500 or more participants) the yearly incidence rate ranges from 37% to 56%. Despite the relatively high incidence rate of running injuries per runner per year, this incidence rate is still 2 to 6 times lower than in virtually all other common sports.
Runners will reduce or cease their training in about 60% to 90% of all reported injuries, will seek medical care in about 20% to 40% of all running injuries, and will curtail their daily non-running routine in about 85% to 95% of running-related injuries.
Most running injuries are musculo-skeletal overuse syndromes related to cumulative overload of the lower extremity. Of all running injuries, 70% to 80% occur from the knee to the foot.
Table 1 (below) lists the 14 most commonly seen and treated running injuries. Of particular note, the knee area is the most common site of injury and accounts for approximately 25% to 33% of all running-related problems.
The pattern of injury varies among different types of distance runners. Although there are no age- or gender-related differences, there are differences in injury pattern between middle-distance and long-distance runners.
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Hamstring strains, tendonitis, backache, and hip problems are more common in middle-distance runners, and stress fractures and foot problems are more commonly seen in long-distance runners. Various knee problems leading to injury are commonly seen in both types of distance runners.
Multiple studies have analyzed the potential risk factors that contribute to running injuries. These risk factors can be broadly separated into extrinsic factors (training errors, improper running surface, worn shoes, etc.) and intrinsic factors (flexibility, prior injury, malalignment, etc.).
The two most important predictors for the overall risk of running injuries are training miles per week and a history of a previous running injury.
* Coaching Resource: Every 800m – 1600m Workout For The Entire High School Season
Increased risk starts at 20 miles per week and the relative risk for running injuries in runners averaging 40 miles per week (common high school average) is 2.88.
Both increased duration and increased tempo of running produces more injuries. Previous injury (in the preceding 12 months) carries a relative risk of a 1.51 multiplier toward a new running injury.
There are several other factors that have been shown to put runners at some increased risk. Inexperienced runners (running three years or less) are at a greater risk for injury. Errors in training such as running too often, too fast, and too long without coach-controlled rest, can increase injury rates.
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There are several risk factors that have been studied and found to have important, equivocal, and unrelated risk factors supporting a direct link with running injuries. These factors are found in Table 2:
* Additional Resource: Training Model for High School Middle Distance (800-1600)
Finally, a thought about running shoes and their link to injury. Running shoes that get wet lose their shock-absorbing ability, and all common running shoes will lose about 30% to 50% of their shock-absorbing characteristics after 250 miles of use.