Impact of core strengthening on chronic mechanical low back pain: a clinical trial based on Saliba’s postural classification

Chronic mechanical low back pain (CMLBP) is frequently associated with abnormal spinal alignment. Core strengthening exercises are extensively used in therapy, however, results may differ depending on postural categorization. This study investigated the effects of core muscle exercises on pain, function, and trunk endurance in patients classified using Saliba’s postural classification system (SPCS). Sixty patients with CMLBP were assigned to one of six postural classification groups (I–VI) of SPCS (10 patients per group) based on photographic analysis and confirmatory clinical tests. For four weeks, abdominal bracing, dynamic stabilization, and advanced core strengthening exercises were performed. Pain intensity, functional disability, and core endurance were assessed using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI), standardized endurance tests, respectively. Assessment was performed pre and post-intervention. A one-way MANOVA and follow up ANOVA tests revealed that there were non-significant differences on reducing pain and functional disability post treatment, F(5,54) = 0.72; P = 0.612; partial ƞ2 = 0.06, F(5,54) = 0.67; P = 0.652; partial ƞ2 = 0.06 for pain and functional disability, respectively. However, specific postural groups demonstrated statistically significant improvements in trunk muscle endurance, particularly in right and left side plank performance, F(5,54) = 3.34; P = 0.011; partial ƞ2 = 0.24 and F(5,54) = 3.80; P = 0.005; partial ƞ2 = 0.26, respectively. A post hoc comparison for plank tests indicated that group I had significantly better right side plank endurance than group V and VI. Also, group I had significantly better left side plank endurance than group II, V and VI. Core muscle strengthening exercises (CMSE) improved trunk muscular endurance in different postural groups, although the reductions in pain and functional impairment were not statistically different. These data indicate that gains in endurance may not directly transfer to similar improvements in pain or function. The study was retrospectively registered at ClinicalTrials.gov (Registration No: NCT06296667) on 5/3/2024. Ethical approval was obtained from the Research Ethical Committee of Faculty of Physical Therapy, Cairo University, Egypt prior to study initiation (Approval No: P.T.REC/012/003644; Date: 27/2/2022).