If the Shoe Fits, Wear It

Sports injuries can be minimized with shoes specific to the sport and playing field

(RxWiki News) Some find it preferable to run on natural grass to avoid getting injured. Others think it's better to step on artificial turf.

And though artificial playing surfaces have changed over the years, it still cannot be determined whether one is better than another in preventing injuries, according to a recently published study.

Researchers emphasized that to keep injuries from occurring, shoes should be specific to the athlete's skill level and the surface being played on.

"Wear the right shoe for the right surface."

Mark Drakos, MD, an orthopedic surgeon at the Hospital for Special Surgery in New York, led a study into how synthetic playing surfaces have evolved and how often injuries on the field have occurred.

The researchers specifically investigated how the interaction between shoes and playing surfaces affected injury rates.

Artificial playing surfaces were created to be more durable than natural grass no matter how often it's used or what kind of weather it endures.

The first generation of artificial playing surfaces were created using nylon in the 1960s. The length of the fibers ranged between 10 and 12 millimeters on average.

The second generation of playing surfaces was created in the 1970s out of polyethylene with 20 to 25 millimeter fibers. The turf was often filled with sand.

The current generation of playing surfaces, which began in the 1990s, is made from proprietary monofilaments that are textured and coated. Rubber and sand fill the inside of these surfaces.

This newer generation behaves more like grass and soil, according to the researchers. The features of each playing surface affect how much energy the athlete takes in at impact.

Older studies have suggested that artificial playing surfaces have led to more injuries, but the researchers found that injuries are often caused by how shoes interact with the playing surface.

With the first generation playing surface, bruises and ankle sprains were common. Common injuries during the second and third generations included anterior cruciate ligament (ACL) and medial collateral ligament (MCL) tears, concussions, sprained ankles and turf toe, or a sprain of the big toe.

"Although previous research suggested that rates of injury are higher on artificial turf than on natural grass, these results must be substantiated based on currently available artificial turf surfaces," the researchers wrote in their report.

"Current data from the NFL suggest that elite athletes may sustain injuries at increased rates even on the newer surfaces; however, these findings have been debated in players below the elite level," they wrote.

The risks that different shoes have on injury cannot be determined yet since weather, shoe wear and field wear have not been taken into account.

When shopping for tennis shoes, the price of the shoe is affected by the quality, rather than the surface the shoes are to be used on, according to Jack Newman, a High Performance coach, CEO of Austin Tennis Academy, and dailyRx Contributing Expert.

Shoes can range in price between $50 to $150. In addition, high performance tennis shoes for all surfaces are more expensive than "normal" tennis shoes for the recreational player, Newman said.

"You can buy tennis shoes to kick around in and you can buy tennis shoes that are built for the stresses of high performance," Newman said.

Other factors that need to be considered include the athletes' body weight, angle of the foot and height before contact, speed, acceleration and deceleration.

In addition, most types of shoes have a peak torque in terms of foot movement and the force of that movement.

The material of the sole and the cleat's pattern and shape can affect the torque. Shoes with smaller cleats have the lowest pressure on the foot, which in turn minimizes the chance of causing foot fractures, according to the researchers.

Torque and strain may be greater on artificial surfaces versus natural grass.

“Optimal shoe-playing surface conditions may be level and sport-specific,” Dr. Drakos in a press release. “The shoe-playing surface interface is a modifiable risk factor for injury, and further research is needed to improve playing conditions for athletes of all levels.”

The study was published in the May issue of the Journal of the American Academy of Orthopaedic Surgeons. The authors did not declare any conflicts of interest.

Review Date: 
May 2, 2013