Effectiveness of hip muscle strengthening in patellofemoral pain syndrome patients: a systematic review

Abstract

Introduction: Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS.Objectives:The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies.Method:A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale.Results:Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies.Conclusion:Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength.

Hip and Knee Strengthening Is More Effective Than Knee Strengthening Alone for Reducing Pain and Improving Activity in Individuals With Patellofemoral Pain: A Systematic Review With Meta-analysis

“…Although most of the trials failed to report the session duration, they provided similar session frequencies (mean ± SD, 3.5 ± 1.4 per week) and program durations (mean ± SD, 6.0 ± 2.5 weeks). In addition, this systematic review included 4 recent randomized trials since the last review was published, 39 and also investigated whether the benefits of intervention are maintained beyond the intervention period.…”

“…4,37,39,44 The first review suggested that hip strengthening had a positive effect on pain reduction, with effect sizes ranging from 0.54 to 0.62. 4 The second review found that the addition of hip strengthening decreased pain during activity (mean difference, -2.2; 95% confidence interval [CI]: -3.8, -0.6) and usual pain (mean difference, -1.8; 95% CI: -2.8, -0.8), but did not change functional ability (standardized mean difference [SMD], 0.6; 95% CI: -0.4, 1.6) in comparison to knee strengthening alone.…”

“…37 The fourth review included 7 randomized clinical trials and concluded that hip strengthening was effective in reducing pain and improving functional capabilities, without changes in strength, compared to no intervention, placebo intervention, or any other type of treatment. 39 A quantitative description of the results was provided, without the benefit of a meta-analysis. 39 Given that different trials have been examined in different reviews and that previous reviews have included a few studies with substantial statistical heterogeneity or did not pool the results from different trials, a meta-analysis of the current evidence is warranted.…”

“…39 A quantitative description of the results was provided, without the benefit of a meta-analysis. 39 Given that different trials have been examined in different reviews and that previous reviews have included a few studies with substantial statistical heterogeneity or did not pool the results from different trials, a meta-analysis of the current evidence is warranted. The aim of this systematic review was to examine the efficacy of knee strengthening, associated or not with hip strengthening (from now on referred to as hip and knee strengthening), to increase strength, reduce pain, and improve activity in individuals with patellofemoral pain.…”

Patellofemoral pain: One year results of a randomized trial comparing hip exercise, knee exercise, or free activity

“…They found no between‐group differences in pain and function despite superior gains in muscle strength for the exercise group, and superior gains in step rate for the gait retraining group. That clinical improvements are not necessarily tied to improvements in muscle strength is observed in two previous systematic reviews . This may suggest that clinical improvements may be moderated by factors other than muscle strength.…”