Running is an inexpensive and convenient form of exercise for an increasing number of adults and generally is associated with positive health benefits. Nevertheless, running can cause musculoskeletal injuries or exacerbate existing conditions. Johnston and colleagues examined the evidence for strategies to prevent injury in runners through training techniques, selection of appropriate shoes, and attention to the running surface.
Training programs should provide appropriate levels of graduated stress interspersed with adequate rest periods, because two thirds of running injuries are attributed to doing “too much too soon.”At least two studies have demonstrated a significant reduction in injuries when novice runners reduced their daily distance and allowed themselves more time to adapt to a running program. Experts have concluded that currently it is not possible to suggest an optimal training load. According to one estimate, men who run more than 64 km (40 miles) weekly would reduce running-related injuries by 15 percent if they ran 48 (30 miles) to 64 km per week instead.
Standard advice for novices is to run at a pace at which they can converse without breathlessness. A walk-run program (see accompanying table) may provide a good introduction to running or re-entry to running for an athlete who has had an injury, although no studies have scientifically validated that such programs reduce injury.
Although studies have shown only a non-significant trend toward higher rates of injury in persons who stretched before running, most experts recommend strengthening and stretching programs to prevent injury. Drop-squat, heel-drop, and hip-abduction exercises are recommended most frequently. Lower extremity stretching exercises also are recommended after running.
Some experts propose that overlooked biomechanical abnormalities in the arch of the foot and the length of the legs predispose some persons to running injuries. When excessive, high arches or flat feet can cause compensatory rotation in the tibia and other mechanical stressors in the legs, leading to pain and predisposing to injury. According to uncontrolled studies, use of orthotic devices can reduce stress fractures and provide positive outcomes in 70 to 80 percent of injured runners, but these results remain controversial. Similarly, a difference in the length of a person's legs has been implicated in running injuries. Treatment of differences in leg length greater than 10 mm that are associated with signs of skeletal compensation have been treated with heel lifts, but the evidence of benefit is anecdotal.
Running in inappropriate shoes exacerbates mechanical problems and predisposes runners to injury. Running shoes are available in many combinations of support and stability and should be selected on the basis of individual running action. After 500 to 700 km (312 to 438 miles) of use, shoes lose shock absorption and should be replaced.
|1||10-minute walk||20-minute walk||30-minute walk|
|2||6x (4.5-minute walk + 0.5-minute run)||6x (4-minute walk + 1-minute run)||6x (3.5-minute walk + 1.5-minute run)|
|3||6x (3-minute walk + 2-minute run)||6x (2.5-minute walk + 2.5-minute run)||6x (2-minute walk + 3-minute run)|
|4||6x (1.5-minute walk + 3.5-minute run)||6x (1-minute walk + 4-minute run)||6x (0.5-minute walk + 4.5-minute run)|
|5||30-minute run||30-minute run||30-minute run|
Any change in training surface is associated with an increased risk of injury. Running on hard surfaces, such as roads and sidewalks, can increase the risk of injury, especially patello-femoral syndrome and tibial stress syndrome. Injuries to the meniscus are associated with running on loose surfaces such as gravel. Running up and down hills increases the risk of iliotibial band friction syndrome and patellar tendinopathy.
The authors conclude that family physicians can prevent some running-associated injuries by encouraging patients to establish a graduated training program, optimizing patients' running mechanics by using orthotics and heel lifts as indicated, advising patients on the selection of appropriate footwear, and emphasizing the role of exercises in improving strength and flexibility.
editor's note: The walk-run program proposed in this article works! After years of avoidance, I tried it myself and can now burn more calories on the treadmill in less time than my previous brisk walking program—and so far I have sustained no injuries. Besides the personal health benefits, advice to patients seems better informed and more effective when based on personal experience, and my colleagues and I have given copies of the program to many of our patients with good results.—a.d.w.