Effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury: a systematic review and meta-analysis

OBJECTIVE: To investigate the evidence relating to the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of musculoskeletal injury. DESIGN: Systematic review and meta-analysis. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Clinical trials evaluating the effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury. DATA SOURCES: Cochrane Library, CINAHL, EMBASE, MEDLINE and SPORTDiscus from their inception up to the first week of June 2016. RESULTS: 11 trials that had evaluated foot orthoses and 7 trials that had evaluated shock-absorbing insoles were included. The median Physiotherapy Evidence Database (PEDro) score for trials that had evaluated foot orthoses and shock-absorbing insoles was 5 (range 3-8/10) and 3 (range 1-7/10), respectively. Meta-analysis found that foot orthoses were effective for preventing overall injuries (risk ratio (RR) 0.72, 95% CI 0.55 to 0.94) and stress fractures (RR 0.59, 95% CI 0.45 to 0.76), but not soft-tissue injuries (RR 0.79, 95% CI 0.55 to 1.14). In contrast, shock-absorbing insoles were not effective for preventing overall injuries (RR 0.92, 95% CI 0.73 to 1.16), stress fractures (RR 1.15, 95% CI 0.57 to 2.32) or soft-tissue injuries (RR 0.92, 95% CI 0.74 to 1.15). CONCLUSIONS: Foot orthoses were found to be effective for preventing overall injuries and stress fractures but not soft-tissue injuries, while shock-absorbing insoles were not found to be effective for preventing any injury. However, further well-designed trials will assist the accuracy and precision of the estimates of risk reduction as the quality of the included trials varied greatly.