The type of running surface, quantity and intensity of training, and type of running shoes may all influence the incidence of injuries in runners. Recent research in this area shows that more compliant or flexible running surfaces, such as grass, may reduce the total stress on the muscles and joints when compared to more rigid surfaces like asphalt and concrete. One study concluded that natural grass exerts less pressure on the foot while running than concrete, asphalt, or rubber surfaces.
Runners have traditionally compensated for hard training surfaces by wearing shoes with considerable cushioning. The research on the relative effects of various surfaces suggests the alternative of running on softer, more forgiving surfaces while wearing less-cushioned shoes. Advocates of this minimalist approach believe that it produces fewer injuries, and some runners have even dispensed with shoes altogether. Such runners would be particularly wise to follow the Kenyans’ example, as running barefoot on streets and sidewalks adds the obvious risk of injuries from debris such as glass.
Several years ago, Runner’s World magazine ran an article detailing 10 different surfaces, weighing the pros and cons of each, and assigning a final rating for each surface. The researchers gave running on snow the lowest rating (2 out of 10), whereas running on grass earned the highest rating (9.5); the study concluded that grass is the best surface to train on, especially for older runners. Every potential running surface has advantages and disadvantages, but a natural surface like grass may be more forgiving than harder manmade surfaces and place less stress on the muscles and joints.
Research published in the The United States Army Medical Department Journal, The Journal of Strength and Conditioning Research, Journal of Sports Sciences, and Research in Sports Medicine supports the medical opinions expressed above.
Dr. James Wyss, Physiatrist at Hospital for Special Surgery, specializes in the non-operative management and rehabilitation of common musculoskeletal and sports injuries. He has a special interest in spinal rehabilitation, interventional spine procedures, the use of ultrasound in musculoskeletal medicine, and injury prevention programs. He is currently a team physician at St. John's University.
Elizabeth (Libby) LaSalle, Department of Physiatry Research Coordinator at Hospital for Special Surgery, contributed to this article.