Monday, September 29, 2008

Cutting-Edge Research: Do Goalkeeper Shorts Offer Protection Against Injury?

The demands of soccer matches and training often place goalkeepers at greater risk of injury than field players. Keepers are routinely knocked to the ground or required dive to the ground in an effort to thwart goal scoring opportunities. Hip injures are particularly common to goalkeepers. They are particularly susceptible to injuries ranging from minor bumps and bruises to major hip fractures. Dr. Kai-Uwe Schmitt of the University and ETH of Zurich has published a pair of research papers that focus on the incidence of goalkeeper hip injuries as well as the ability of padded short to protect the athlete. Dr. Schmitt found that goalkeepers suffer a number of injuries to the hip, especially during training, and that protective shorts do little in the way of prevention. His papers appear in recent issues of the British Journal of Sports Medicine and Sportverletzung Sportschaden.

In the first part of their study, Dr. Schmitt and colleague surveyed over 250 male and female goalkeepers as well as a number of medical personnel. The keepers were either professional players from top-level Swiss and German leagues or amateur players from lower levels of the same leagues. They were all asked about the type of injuries sustained to the hip as well as the circumstances surrounding each injury.

The researchers found that the most common type of injuries were bruises (contusions) and abrasions to the hip area. Nearly all of the goalkeepers surveyed said that they had received at least one of these types of injuries over the course of the season. There were far fewer major injuries such as fractures or chronic problems such as bursitis or arthritis. Only three athletes sustained a hip fracture.

Most of the injuries were sustained during training as compared to matches. This is to be expected given that far more hours are spent training than playing matches. Also, amateur goalkeepers had a greater injury incidence than professionals. There was a trend for more injuries to occur on artificial fields than on natural grass but this difference was within the studies’ margin on error.

The second part of the research focused on the use of padded shorts. The survey results indicated that there were no differences in the incidence of injury between those keepers who wore padded shorts and those that did not. The researchers followed up on this finding by performing mechanical analyses on 12 different varieties of commercially available shorts. Shorts were obtained from Adidas, Kappa, Puma, Nike, Lotto, Joma and McDavid). The mechanical tests were designed to rate the ability of the shorts to resist impact forces and to protect the hip from injury. All of the shorts performed poorly on the tests and offered very little in the way of protection from severe injury. Thus, the researchers concluded that the thin (~1 cm) layer of padding found in goalkeeper shorts offers very little protection for the athlete. They also suggest that manufacturers focus on designing shorts to prevent contusions and abrasions, the types of injuries that are more common among goalkeepers.

This study provides two pieces of evidence suggesting that padded goalkeeper shorts are not terribly effective in preventing hip injuries. First, their survey results show that the incidence of injury is the same for players wearing goalkeeper shorts and those wearing regular shorts. Second, the mechanical testing revealed that the padding found in commercially available goalkeeper shorts dos very little to reduce impact forces on the hip. Based on this information, one may question whether shorts designed specifically for goalkeepers are worth the investment. However, these shorts can range in price from $20-50, not markedly more than a pair of quality field player shorts. Also, there is no indication that goalkeeper shorts places athletes at greater risk. Therefore, the choice of whether not to use goalkeeper shorts boils down to personal preference rather than to a scientific recommendation.

References:

Schmitt KU, Nusser M, Boesiger P (2008) Hip injuries in professional and amateur goalkeepers. Sportverletzung Sportschaden, 22:`59-`63.

Schmitt KU, Nusser M, Denter S, Boesiger P (2008) Analysing the protective potential of padded goalkeeper shorts. British Journal of Sports Medicine, doi: 10.1136/bjsm.2008.048058.