Effect of Low-Load, Long-Duration Stretching on Pain and Mobility in Sacroiliac Joint Dysfunction

Background: Sacroiliac joint dysfunction (SIJD) is a significant contributor to low back pain, often causing postural deviation and restricted mobility, disrupting daily life. In this study, a low-load, long-duration (LLLD) stretching protocol was compared to a conventional stretching protocol to evaluate the effects of each intervention. LLLD stretch is a burgeoning technique that applies sustained mild tensile force to augment tissue elasticity, dissipate pain, and enhance joint mobility. Methods: This investigation employed a comparative study design enrolling 120 participants. The Numerical Pain Rating Scale (NPRS), provocative tests, Timed Up and Go (TUG) test, and limb length discrepancy (LLD) were employed as assessment tools in this study. The participants underwent a detailed protocol targeting the hamstrings, iliopsoas, piriformis, and thoracolumbar fascia. Statistical evaluation involved intragroup comparisons conducted using paired-samples t-tests. Intergroup differences in post-intervention outcomes were evaluated using a baseline-adjusted analysis of covariance (ANCOVA) to control for initial scores as a covariate. Results: Following baseline adjustment, the experimental group demonstrated a greater reduction in pain (NPRS) compared to the control group (F = 65.11, p < 0.001, partial eta squared (ηp2) = 0.360), with an adjusted mean difference of 1.68. The correction of apparent LLD was also more effective in the experimental group (F = 136.43, p < 0.001, ηp2 = 0.538). While both groups showed significant within-group improvements in functional mobility (TUG), no significant between-group difference was observed after adjusting for baseline values (p = 0.442). Conclusion: The integrated LLLD stretching protocol is more effective for achieving pain relief and functional symmetry in SIJD compared to conventional stretching. However, improvements in general functional mobility remain comparable between the two intervention strategies.