Gluteus medius muscle function in people with and without low back pain: a systematic review.
Level 4 - case-series / case-control
Systematic review of case-control studies
PubMed 31638962 · doi:10.1186/s12891-019-2833-4
What was done
Authors conducted a systematic review across eight electronic databases (MEDLINE, EMBASE, AMED, PsycINFO, PubMed, ProQuest, CINAHL, SPORTDiscus) from inception to December 2018. Inclusion was restricted to case-control studies comparing quantifiable gluteus medius muscle function (strength, activation, morphology) between adults (18+ years) with any type/duration of low back pain and pain-free controls. Two reviewers performed independent screening, quality appraisal, and data extraction.
What was found
Twenty-four articles were included (1,088 participants with low back pain and 998 without). Participants with low back pain tended to demonstrate reduced gluteus medius strength and more trigger points compared to controls. Results for activity level, fatigability, time to activate, time to peak activation, cross-sectional area, and muscle thickness were unclear. The abstract reported no numerical effect sizes or confidence intervals, and meta-analysis was not performed due to study heterogeneity.
Why it matters
This review aggregates existing case-control literature suggesting that gluteus medius weakness and trigger points frequently co-occur with low back pain, pointing to potential targets for clinical assessment.
Limits
The underlying evidence is limited entirely to case-control designs, precluding causal inferences regarding whether gluteus medius alterations precede or follow low back pain. Wide heterogeneity in low back pain definitions, chronicity, and functional measurement protocols prevented quantitative meta-analysis.