Meta-Analysis
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Apr 26, 2015; 3(2): 118-124
Published online Apr 26, 2015. doi: 10.13105/wjma.v3.i2.118
Addition of hip exercises to treatment of patellofemoral pain syndrome: A meta-analysis
Kimberly M Morelli, Maria Carrelli, Maria A Nunez, Caroline A Smith, Gordon L Warren
Kimberly M Morelli, Maria Carrelli, Maria A Nunez, Caroline A Smith, Gordon L Warren, Department of Physical Therapy, Georgia State University, Atlanta, GE 30302-4019, United States
Author contributions: All authors contributed to the design of the research study and interpretation of data; Morelli KM, Carrelli M, Nunez MA and Smith CA contributed to the acquisition of data as described in the methods; Morelli KM and Warren GL performed the data analyses and wrote the manuscript.
Conflict-of-interest: The authors have declared no conflict of interest related to the manuscript.
Data sharing: Technical appendix, statistical code, and dataset available from the corresponding author at gwarren@gsu.edu.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Gordon L Warren, Professor, Department of Physical Therapy, Georgia State University, P.O. Box 4019, Atlanta, GE 30302-4019, United States. gwarren@gsu.edu
Telephone: +1-404-4131255 Fax: +1-404-4131230
Received: November 5, 2014
Peer-review started: November 5, 2014
First decision: January 20, 2015
Revised: February 13, 2015
Accepted: March 30, 2015
Article in press: April 2, 2015
Published online: April 26, 2015
Processing time: 174 Days and 4.1 Hours
Abstract

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 review searching eight databases (i.e., PubMed, Cochrane, CINHAL, MEDLINE, SportsDiscus, 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.

Keywords: Exercise therapy; Systematic review; Knee joint; Physical therapy modalities

Core tip: The most effective treatment to improve pain and function in patellofemoral pain syndrome is uncertain. We performed a systematic review and meta-analysis to determine if the addition of hip-strengthening exercises to traditional physical therapy interventions could effectively reduce pain and increase function in patients with patellofemoral pain syndrome. Our analysis indicates that the addition of hip-strengthening exercises provides a significant and relatively large additional reduction in pain and increase in function.