Oslo Sports Trauma Research Center

Intoduction

Systematic analysis of videos of ankle injuries provides detailed information on the injury mechanisms - both for lateral ligament sprains and for the condition dubbed footballers ankle. Mainly, ankle injuries occur in tackling duels and most often the injured player is tackled late from the side, according a new study from the Oslo Sports Trauma Research Center published in January 2004 in the American Journal of Sports Medicine

Video analyses of ankle injuries provides detailed information on the injury mechanisms

The Oslo Sports Trauma Research Center initiated an in-depth study to describe the specific injury mechanisms for ankle injuries using video recordings. Videotapes and injury information were collected for 313 of 409 regular league matches in the elite Norwegian and Icelandic male soccer leagues during the 1999-2000 seasons. Video recordings of incidents that resulted in ankle injuries were analyzed and cross-referenced with injury reports from the team medical staff. An injury was recorded if the player was unable to participate in training or match play for at least one day following the incident.

A total of 46 acute ankle injuries were reported to have occurred, i.e. 4.5 injuries per 1000 match hours. Of these, 26 (57%) were identified on the videotapes, 23 ligament sprains and three contusions. The video analysis of the 26 ankle injuries showed that 14 occurred during tackling and 4 during clearing/shooting. In ten of the 14 tackling incidents, the injured player was tackled. Of these, six were classified as a late tackle.

Two mechanisms thought to be specific to soccer were found: 1) player-to-player contact with impact by an opponent on the medial aspect of the leg just before or at foot strike, resulting in a laterally directed force causing the player to land with the ankle in a vulnerable, inverted position, and 2) forced plantar flexion where the injured player hit the opponents foot when attempting to shoot or clear the ball.

This study showed that a thorough video analysis can provide detailed information about the mechanisms of ankle injuries in soccer. Most ankle injuries occurred in tackling duels where the injured player was tackled in a late tackle from the side. The most frequent injury mechanism found was player-to-player contact with impact on the medial aspect of the lower leg or ankle of the injured player. Most likely, this laterally directed force caused the player to land with the ankle in a vulnerable, inverted position. In addition, we observed four cases where the injured player hit his opponents foot, resulting in forced plantar flexion of the ankle. This mechanism may explain the condition dubbed footballers ankle.

Ankle injuries are frequent in football, and until now, attempts at preventing these have focused on balance training and taping or bracing. Both these techniques have been shown to be effective to prevent recurrent injuries in players with recent previous injuries. However, no strategy exists to prevent primary injuries in football players. The current study suggests that if the number of late tackles towards the ankle and lower leg can be reduced, it may be possible to reduce the frequency of ankle injuries, as well. Referees are trained to focus on dangerous play, but require education about which specific playing actions that are associated with a high risk of injuries. There may be a need to amend the Laws of the Game to protect players from dangerous play in duels, by imposing stricter penalties for late tackles from the side or from behind.

The primary investigator for this study was Thor Einar Andersen MD, in cooperation with stud med Tonje Waale Floerenes, PhD student Árni Árnason PT and professor Roald Bahr MD PhD.