The effect of knee valgus control feedback exercise on pain, hip torque and performance variables in participants with patellofemoral pain

 Aims and background: Patellofemoral pain syndrome (PFPS) is a common knee disorder frequently occurred in young females. Abnormalities of lower limb movement patterns during weight-bearing activities can directly affect referred pain. The purpose of this study was to determine the effect of knee valgus control feedback exercise on pain, eccentric hip muscle torque, performance and knee angle in females with PFPS. Materials and methods: 32 women with PFPS with mean age 22.6±6.18 years selected and were divided into experimental (n=16) and control (n=16) groups. The isokinetic dynamometer, visual analogue scale (VAS), 4 lower extremity performance tests includes (single leg hop test, triple hop test, crossover hop test and single leg 6m timed hop test) and single leg squat were used respectively in order to measure eccentric hip muscle torque, pain, performance and knee angle. The Shapiro-Wilk, repeated measure, paired and sample t tests were used for statistical analysis (significance level α≤0.05). Findings: Based on the findings of this study, the significant changes were reported in experimental group in hip abductor to adductor ratio (P=0.001) hip external to internal rotation ratio (P=0. 001), pain (P=0. 001), and all performance tests (P=0. 001) and knee valgus angles were (P=0. 001), that indicate knee valgus control feedback exercises improve the hip torque ratio, pain, dynamic knee valgus angle and performance. Conclusions: The results revealed that, dynamic knee valgus control feedback exercises have a beneficial effect on PFPS participants due to alteration in biomechanical variables such as eccentric hip muscle torque, performance variables, knee dynamic valgus angle and pain.