Research Review by Dr. Shawn Thistle©


Aug. 2007

Study Title:

Prevention of sports injuries
Systematic review of randomized controlled trials


Aaltonen S et al.

Publication Information:

Archives of Internal Medicine 2007; 167(15): 1585-1592.


It is well known that sport and leisure activities can lead to injuries. The incidence of sports injuries is estimated to be 15-25 per 1000 population per year, and many of these people seek care from manual therapists. Currently, athletes at all levels of competition utilize different methods to prevent sports injuries, ranging from prophylactic braces and devices to training techniques. Several of these methods have been studied in randomized trials, but overall the results for most options are inconclusive and often conflicting.

Only one systematic review of studies investigating the prevention of sports injuries has been published recently (2001), but this study did not include quality assessment of the trials. In addition, new studies have emerged since that review was published. Therefore, the purpose of this systematic review was to summarize the effects of interventions targeted at preventing sports injuries.

Relevant databases were searched for applicable studies. To be selected for this review a trial had to investigate the effect of any preventive intervention on sports injuries. Studies also had to be randomized or quasirandomized, controlled, and published before January 1, 2006.

Each study was evaluated using 11 criteria (recorded on a yes/no basis), similar to those used in the familiar Jadad Scoring System (ex. randomization, participant blinding, concealed allocation, dropout rate, etc.). Studies were grouped by intervention to simplify reporting and analysis, despite the fact that the interventions used were not exactly the same in each study. Statistical pooling was performed when appropriate. The categories of studies will be reviewed individually below:

Shoe Insoles
  • 5 trials including 2466 participants (all military recruits) were analyzed – each investigated the effect of shoe insoles (custom or pre-fabricated) on lower extremity injuries
  • all 6 trials showed a trend toward preventive effects of insoles (all showing an injury risk reduction of 30% or more, and 4/6 trials showing a risk reduction of 50% or more)
  • the studies that showed the largest effect sizes contained the smallest number of participants
  • the effectiveness of custom made and pre-fabricated insoles was statistically similar
External Joint Supports (7 studies, 10 300 patients)
  • 4 studies investigated ankle orthoses, ankle stabilizers, and outside-the-boot ankle braces – all tended to reduce ankle injuries (effect size was > 50%, and statistical significance was obtained in 3 of 4 studies)
  • 2 studies investigated wrist supports in snowboarding – both showed a trend of risk-reduction for wrist injuries (Odds Ratios 0.12 and 0.27 respectively)
Training Programs
  • 4 trials (1799 subjects) tested balance board training for preventing ankle sprains – these studies produced contradictory results (again, the highest effect size was in the study with the fewest participants)
  • 2 multi-interventional trials (400 subjects) utilizing balance board training, and 4 multi-interventional trials (2409 subjects) that did not utilize balance boards ALL showed favourable results for their interventions
  • overall, the literature in this area is inconclusive
General Comments &  Other Interventions
  • none of the 3 trials on stretching and warm-up programs (3500+ subjects) showed preventive effects
  • overall, the state of the literature in the area of sports injury prevention is poor
  • of the studies used in this review, the highest quality score was 8/11, and the average score was only 3.8/11 – indicating low general methodological quality
  • a comprehensive meta-analysis was not performed due to limitations relating to clinical and methodological diversity of the studies
  • it should be noted that most of these studies are performed on military recruits, perhaps limiting the external validity of the findings – the results may apply less to athletes, but more to previously inactive people who start training programs
  • the studies that showed the largest treatment effects generally had the smallest sample sizes

Conclusions & Practical Application:

This review emphasizes the need for further high quality studies in this area. The results of the studies contained in this review provide the basis for future work, but unfortunately do not provide solid, evidence-based answers surrounding this topic. Future studies are required in all areas of injury prevention, and special consideration should be given to:
  • examining compliance with prophylactic devices
  • commonly practiced, high-risk sports, including modern sporting trends (ex. extreme sports)
  • cost-effectiveness of certain interventions and devices
  • whether long-term prevention is achieved with proper adherence
  • specific training methods and their impact on injury prevention
  • how manual therapy techniques can assist in injury prevention (and of course, recovery)
  • incorporating larger patient groups in higher quality studies