Feasibility of Spinal Manual Therapy Interventions for a Future Clinical Study of Back Pain

Clinical trials of spinal manual therapy interventions for back pain and back-related leg pain face methodological challenges regarding the design of effective sham control ('control' hereafter) and blinding of the assigned interventions. Although the assessment of blinding is often neglected in the field of manual medicine, the implementation of high-quality trials of spinal manual therapy interventions warrants formal evaluation of blinding feasibility among participants and outcome assessors to advance randomized clinical trial methods and design. The objectives of this blinding feasibility trial are: 1. To assess the feasibility of blinding participants, with or without experience of spinal manual therapy or current low back pain, randomly allocated to an active or control spinal manual therapy intervention protocol. 2. To assess the feasibility of blinding managing clinicians (non-treating clinicians or outcome assessors) within the randomised trial context. 3. To examine the impact of spinal manual therapy experience in the past 3 months (Yes vs No) and presence of low back pain during the past four weeks (average intensity ≤2 versus ≥3 out of 10) on the feasibility of participant and managing clinician blinding. 4. To explore factors contributing to participant and managing clinician perceptions about the assigned intervention (active versus control) using a qualitative thematic analysis.