Effectiveness of Abdominal Hollowing and Piriformis Stretching Exercises in Spondylolisthesis Patients: A Study Protocol for a Randomized Controlled Trial

Background Lumbar spondylolisthesis is a clinically important cause of chronic low back pain, activity limitation, and reduced functional capacity. Exercise-based physiotherapy is widely recommended for conservative management, yet uncertainty remains regarding the added value of targeted core stabilization and hip-related stretching strategies in this population. Abdominal hollowing is intended to improve deep trunk muscle activation and lumbopelvic control, whereas piriformis stretching may reduce posterior hip tightness and movement-related discomfort. This trial aims to evaluate whether adding abdominal hollowing and piriformis stretching exercises to a standardized conventional physiotherapy programme improves pain, functional disability, and kinesiophobia in adults with low-grade lumbar spondylolisthesis. Methods This study is a two-arm, parallel group, assessor-blinded randomized controlled superiority trial. Seventy-two participants aged 18 to 65 years with radiologically confirmed lumbar spondylolisthesis of Meyerding grade I or II, chronic localized low back pain of more than 3 months, and a baseline pain intensity of more than 3 on a 10-point visual analogue scale will be recruited from the Musculoskeletal Physiotherapy Unit of the Centre for the Rehabilitation of the Paralysed, Savar, Bangladesh. Recruitment is planned from April 2026 to June 2026. Participants will be allocated in a 1:1 ratio using a computer-generated block randomization sequence with concealed allocation. Both groups will receive a standardized conventional physiotherapy programme three times weekly for 6 weeks. The experimental group will additionally receive abdominal hollowing and piriformis stretching exercises. Primary outcomes will be pain intensity measured by the Visual Analogue Scale, functional disability measured by the Oswestry Disability Index, and kinesiophobia measured by the Tampa Scale for Kinesiophobia. Outcomes will be assessed at baseline, immediately after the 6-week intervention, and at 4-week follow-up. Data will be analyzed according to the intention-to-treat principle using linear mixed effects models, with effect estimates reported alongside 95 percent confidence intervals. Discussion This trial will determine whether adding targeted core stabilization and piriformis stretching to a standardized physiotherapy programme produces superior short-term clinical outcomes in people with lumbar spondylolisthesis. The findings may inform conservative rehabilitation strategies for this population, particularly in resource-limited clinical settings. Trial registration: Clinical Trial Registry India (CTRI), CTRI/2025/07/089927. Registered prospectively on 01 July 2025.