Limited Support for Trunk and Hip Deficits as Risk Factors for Athletic Knee Injuries: A Systematic Review With Meta-analysis and Best-Evidence Synthesis

OBJECTIVE: To determine whether neuromuscular deficits in trunk and hip-related function are risk factors for athletic knee injuries. DESIGN: Etiology systematic review with meta analysis. LITERATURE SEARCH: Six online databases (MEDLINE, Web of Science, Embase, CINAHL, Scopus, and SPORTDiscus) were searched up to April 2019. STUDY SELECTION CRITERIA: Studies assessing trunk and hip neuromuscular function as risk factors for knee injuries in healthy athletic populations were included. DATA SYNTHESIS: Outcomes were synthesized quantitatively using meta-analysis of odds ratios, and qualitatively using best-evidence synthesis. RESULTS: Twenty-one studies met the inclusion criteria. There was very low-certainty evidencethat greater hip external rotation strength protected against knee injuries (odds ratio = 0.78; 95% confidence interval: 0.70, 0.87; P<.05). There was limited evidence that deficits in trunk proprioception and neuromuscular control, and the combination of excessive knee valgus and ipsilateral trunk angle when landing unilaterally from a jump, may be risk factors for knee injuries. CONCLUSION: Most variables of trunk and hip function were not risk factors for injuries. Further research is required to confirm whether hip external rotation strength, trunk proprioception and neuromuscular control, and the combination of knee valgus angle and ipsilateral trunk control are risk factors for future knee injuries.