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Rogan S.1,2, Hähni M.1, Taeymans J.1
1Bern University of Applied Sciences, Health, Bern, Switzerland, 2Academy of Physiotherapy and Training Education, Grenzach-Wyhlen, Germany
Background: Treatment of patellofemoral pain (PFP) focuses on the neuromuscular control of the knee. An extensive systematic review on the treatment effects of proximal exercises (e.g. strengthening of quadriceps muscle, hip muscles and abdominal muscles) on PFP, observed high between study effect size heterogeneity which did not allow for pooling of the data.
Purpose: To conduct a systematic review and meta-analysis by focusing on the role of the gluteal muscles only in the management and therapy of PFP. The aims of this study were (i) to assess the effect of hip muscle strengthening compared to no hip muscle strengthening training and (ii) to estimate the effect of hip muscle strengthening compared to knee muscle strengthening on pain and function in patients with PFP.
Methods: Eligible studies examining the impact of strengthening of hip abductor muscles, no hip muscle exercise or knee muscle exercise on pain and functional status were selected in six databases. The Cochrane risk of bias tool was used to assess procedural quality. Trial registration: PROSPERO 2014:CRD42014010716.
Results: Seven RCT studies and one non-RCT study were included totaling 291 participants. The studies showed on average a low methodological quality. Hip exercise revealed greater pain reducing effects (Hedges´g = - 1.2, 95% CI: - 2.2 to - 0.2) as compared to no hip exercise and as compared to knee muscle training (Hedges g = - 0.7, 95% CI: - 1.7 to 0.2). After re-expression in the original metric, these effect sizes translate into a reduction by 1 to 2 cm on the 10 cm VAS pain scale. The effectiveness on functional impairment in the hip exercise group compared to the no hip exercise, revealed a Hedges´g = -1.5 (95% CI: 3.1 to 0.01). Compared to knee muscle training this effect was Hedgesg = -0.9 (95% CI: -2.0 to 0.3), indicating functional improvement after hip strength exercise. Clinically, this finding is consistent with a reduction by about 20 units on the Lower Extremity Functional Scale (LEFS). In this review more studies assessing open-chain hip exercises than closed-chain hip exercises were included. Both training methods showed similar improvements in functional status and hip muscle strength.
Conclusion(s): The results of the meta-analysis showed evidence that strength training of the hip abductor muscles compared to no hip muscle training had a strong and statistically significant effect on pain and function in patients with PFP. Furthermore, hip muscle training compared to knee muscle training showed also clinically relevant effect-sizes on pain and function in patients with PFP (albeit not statistically significant).
Implications: Open-chain hip exercises as well as closed-chain hip exercises showed clinically relevant improvements in functional status and hip muscle strength.
Funding acknowledgements: None
Topic: Musculoskeletal: peripheral
Ethics approval: None
All authors, affiliations and abstracts have been published as submitted.
