The effect of kinetic factors of dynamic knee valgus on patellofemoral pain: A systematic review and meta-analysis.

The speculation of dynamic knee valgus (DKV) correlates with kinetic changes in the frontal plane that increased loading patellofemoral joint (PFJ). Therefore, it is the purpose of this systematic review and meta-analysis study is the effect of kinetic factors DKV on patellofemoral pain (PFP). The search strategy was carried out in the electronic databases of Cochrane Library, PubMed, Springer Link, Science Direct, Scopus. Studies limited to the period 2000 to 2020 were extracted. The quality of study was assessment by modified Downs and Black checklist. Mean and standard deviation were also used to calculate the effect size. There were selected 8 articles for the systematic review and Meta-analysis. The results showed that in PFP patients compared to healthy individuals have increase knee abduction moment (SMD = 0.75; 95% CI = [0.47 to 1.02]) and impulse (SMD = 0.79; 95% CI = [0.50 to 1.07]). Furthermore, PFP patients compared to healthy individuals have decrease onset (SMD = -0.60; 95% CI = [-1.03 to -0.17]) and during (SMD = -0.93; 95% CI = [-1.57 to -0.29]) gluteus medius (GMED); vis-à-vis, PFP patients compared to healthy individuals have increase onset (SMD = 0.10; 95% CI = [-0.34 to 0.54]) and during (SMD = 0.29; 95% CI = [-0.15 to 0.73]) adductors longus (AL). As a result; PFP patients compared to healthy individuals show decrease co-contraction GMED/AL (SMD = -1.03; 95% CI = [-1.83 to -0.24]). The kinetic factors of DKV of leading to PFJ contact area decreases and the loading in a smaller contact area on PFJ in the outer part of the patella. Eventually, this abnormal distribution of contact pressure leads to etiology and osteoarthritis of the PFP.