Oslo Sports Trauma Research Center

Intoduction

A new study in the American Journal of Sports Medicine by Evert Verhagen (who has been a visiting scientist at the Oslo Sports Trauma Research Center during the fall of 2002) proves that proprioceptive balance board training is effective for the prevention of recurrent ankle sprains. A one season proprioceptive balance board training programme that was incorporated in the training routine of 66 Dutch volleyball teams significantly reduced the incidence of ankle sprains when compared to a control group of 50 similar Dutch volleyball teams.

Training on balance board prevents new injuries effectively

The majority of contemporary sports entails physical activity, and relatively recently the potential of these physical activities in the prevention of chronic diseases has been recognised. This has caused that today people of all ages are encouraged to have a physically active lifestyle and to actively participate in sports. However, participation in sports also has its downside in the form of injuries. Acute lateral ankle ligament injuries (ankle sprains) are the most common injuries across a wide variety of sports. Athletes who suffer from ankle sprains are

more likely to re-injure the same

ankle, which can result in disability and can lead to chronic pain or instability in 20 to 50% of these cases. This high incidence of ankle sprains and their negative consequences for future sports participation, calls for preventive measures.

Braces and tape are widely used measures against ankle sprains. It is known from previous research that braces show a reduction in ankle sprain incidence, and it is argued that tape also has a preventive effect, since the working mechanism is thought to be similar to braces. However, both measures have negative side-effects; e.g. while braces can be irritating if not fitting properly and are argued to negatively affect performance, tape loosens during play, needs to be applied by qualified personnel, and can cause skin irritation. Proprioceptive balance board training is another measure, presumably as effective as braces and tape is, but without the above mentioned negative side effects. This measure is already used in the rehabilitation following ankle sprain, in order to re-strengthen muscles and ligaments, and to restore proprioception of the damaged structures around the ankle. Proprioceptive balance board training has also been suggested as an alternative to taping or bracing in the prevention of ankle sprains. Previous studies showed that this method is promising in doing so. However, these previous studies failed to show a significant reduction of ankle sprains, presumably due to low sample size and/or inadequate study design.

In order to establish the effect and cost-effectiveness of a proprioceptive balance board training programme for the prevention of ankle sprains, 116 Dutch male and female volleyball teams were followed prospectively during one volleyball season. Teams were randomized by four geographical regions to an intervention group and control group. While control teams followed their normal training routine, intervention teams followed a prescribed balance board training programme. Volleyball exposure during training and matches, as well as injuries was recorded for each individual player on a weekly basis. If a player sustained an ankle sprain a cost-diary was completed for the duration of the injury.

In the intervention group significantly less ankle sprains were found as compared to the control group (risk difference = 0.4 per 1,000 playing hours; 95% CI: 0.1 0.7). This significant reduction in ankle sprain risk was found only for players with a history of ankle sprains. Since only an effect was found for players with previous injury, which is a known risk factor for re-injury, the effect of the balance board training programme should be regarded as a rehabilitative effect rather than a primary preventive effect.

The total costs per player (i.e. including the intervention material) were significantly higher in the intervention group (Euro 36.99 ± 93.87) as compared to the control group (Euro 18.94 ± 147.09). The price to prevent one ankle sprain was approximately Euro 444.03. However, a sensitivity analysis showed that the costs associated with the balance board programme will be lower  and might even prove cost-beneficial when the target population would be defined more strictly and when a prolonged use of the intervention material would be taken into account.

The present study was conducted in volleyball and provides evidence for a preventive effect of a proprioceptive balance board training programme in this sport. However, since the injury mechanism underlying ankle sprains as well as the risk of injury recurrence are universal across all sports, the use of a balance board programme is recommended for all players with a history of ankle sprains participating in a wide variety of sports.

This study was performed at the EMGO-Institute of the VU University Medical Center in Amsterdam, the Netherlands. Evert Verhagen PhD conducted the study with his colleagues professor Willem van Mechelen MD, professor Lex Bouter, and Allard van der Beek PhD. This study was also carried out in cooperation with professor Roald Bahr the chair of the Oslo Sports Trauma Research Center, who had a major contribution in analysing and writing up this study for publication.