Addition of hip exercises to treatment of patellofemoral pain syndrome:A meta-analysis

AIM:To determine if the addition of hip-strengthening exercises decreases pain and improves function in patients with patellofemoral pain syndrome.METHODS:The authors completed a systematic reviewsearching eight databases(i.e.,Pub Med,Cochrane,CINHAL,MEDLINE,Sports Discus,EMBASE,APTA Hooked on Evidence,and PEDro).Two independent reviewers screened and excluded studies if they did not meet the following inclusion criteria:subjects had a primary diagnosis of patellofemoral pain syndrome(PFPS),intervention group included hip-strengthening exercises,control group included a traditional physical therapy intervention,study included outcome measures of pain and/or function,study used a randomized controlled trial design,PEDro score was ≥ 7,and study was published in a peer-reviewed journal.Primary outcome measures were subjective scales of pain and function.These measures were converted to standardized mean difference [effect size(ES)],and a random-effects model was used to calculate the overall ES.RESULTS:Two hundred eighty-three studies were screened for inclusion in our meta-analysis.Nine studies were deemed suitable for data extraction and analysis.A total of 426 subjects were used in the nine studies.Overall,there was a significant positive effect of hip-strengthening exercises on measures of pain and function in subjects with PFPS(ES = 0.94,P = 0.00004).None of the individual studies had a negative ES,with study ES ranging from 0.35 to 2.59.Because of the high degree of between-study variance(I2 = 76%;Q = 34.0,P < 0.001),subgroup meta-analyses and meta-regressions were performed.None of the potential moderator variables that were investigated(e.g.,outcome type,hip region targeted,duration of treatment) could explain a significant amount of the between-study variance in ES(P ≥ 0.23).CONCLUSION:Overall,the addition of hip-strengthening exercises to traditional physical therapy produced greater improvements in measures of pain and function.