Rathleff et al. 2014, Is hip strength a risk factor for patellofemoral pain?

Systematic review and meta-analysis (M S Rathleff, C R Rathleff, K M Crossley, C J Barton; British Journal of Sports Medicine 48(14):1088, 2014; DOI 10.1136/bjsports-2013-093305) of 21 cross-sectional and 3 prospective studies. Adults with patellofemoral pain show lower hip strength than pain-free people in cross-sectional data, but the prospective studies found no association between isometric hip strength and the later development of the condition. The authors conclude hip weakness may be a result of the pain rather than its cause. Moderate-to-strong evidence on the prospective question.