Computerized Instrument-Assisted Spinal Manipulation with or Without Exercise for Chronic Nonspecific Low Back Pain: Week-8 Findings from a Three-Arm Randomized Controlled Trial

Background: Computerized instrument-assisted spinal interventions may standardize mechanical impulse delivery, but clinical evidence in chronic nonspecific low back pain remains limited. Methods: In this three-arm randomized controlled trial, 135 adults were assigned (45/group) to instrument-assisted treatment (FYS), FYS plus core-based exercise (FYS + EX), or core-based exercise alone, with blinded outcome assessment. The trial was not prospectively registered. Following an audit identifying baseline VAS duplication, week-12 duplication, and unverifiable individual longitudinal linkage within the retained workbook, week-8 outcomes were analyzed as between-group endpoints using group-only linear models with HC3 robust standard errors or Fisher exact tests for Slump status, with Holm adjustment within each endpoint. Results: Compared with exercise alone, FYS and FYS + EX had higher week-8 straight-leg raise (+27.53° and +34.42°), lower Oswestry Disability Index (−46.47 and −45.36 points), and lower VAS pain (−21.00 and −10.00 points; all Holm-adjusted p < 0.001). FYS + EX had higher SLR (+6.89°), similar disability, and higher pain (+11.00 points) than FYS. Adverse events were monitored during intervention; the investigator reported none. Conclusions: The week-8 between-group contrasts were large but require cautious interpretation. The treating investigator confirmed the week-8 observations and the clinical treatment sequence; nevertheless, the archived workbook does not independently establish participant-level linkage or permit external source-data verification. The unusually large effects, incomplete archived trial documentation, and unavailable treatment-dose records preclude definitive efficacy or safety conclusions.