The relationship between hip strength and knee valgus during dynamic tasks among male and female adults with and without symptomatic knee pain: a systematic review

Background Previous systematic reviews regarding the association among hip strength and dynamic knee valgus were limited to asymptomatic female adults. Aims The focus of the current systematic review was to examine the association between hip muscle strength and knee kinematics while performing dynamic tasks across male and female adults, with and without knee pain. Methods Four databases (Scopus, SAGE, Science Direct, and Pubmed) were searched from inception to December 2020. The review included studies that examined the association between hip muscle strength and knee kinematics during various tasks in male and female healthy adults or patients. Results A total of 733 participants (female = 587; male = 146; patients = 69; healthy = 664) from 13 studies met the inclusion criteria. Twelve studies found an association between peak knee valgus and reduced hip strength, indicated that increased hip strength would minimize knee valgus in various dynamic tasks. Only one study that involved elite female soccer players showed no correlation between knee valgus and hip strength. Conclusions The association between hip strength and knee valgus is influenced by the tasks demand, pain, gender, and fitness level of the participants. The review showed that hip strength has substantial role in dynamic knee valgus modulation during functional activities. Coaches and athletes may focus on hip muscle strengthening to reduce the risks of non-contact injuries associated with excessive dynamic knee valgus. The protocol of this review has been registered on 5th December 2020 at PROSPERO with registration number: CRD42020219135.