Chronic nonspecific low back pain is one of the most common causes of pain and disability worldwide. Many people with chronic low back pain experience difficulties with balance, posture, movement control, and daily activities. Sensorimotor balance training is a rehabilitation approach designed to improve balance, body awareness, and neuromuscular control.

The purpose of this randomized controlled trial is to investigate whether sensorimotor balance training is more effective than standard physiotherapy in reducing pain and improving spinal alignment in adults with chronic nonspecific low back pain. Participants will be randomly assigned to either a sensorimotor balance training group or a standard physiotherapy group. Both groups will receive treatment three times per week for 12 weeks.

Pain intensity, functional disability, and spinal alignment will be assessed before and after the intervention. Spinal alignment will be measured using the DIERS Formetric 4D system, a non-invasive and radiation-free technology that evaluates posture and spinal shape. The findings of this study may help identify effective rehabilitation strategies for improving pain, function, and spinal alignment in people with chronic nonspecific low back pain.

Chronic nonspecific low back pain (CNSLBP) is a major cause of disability and reduced quality of life worldwide. In addition to pain, individuals with CNSLBP frequently demonstrate impairments in sensorimotor control, proprioception, postural stability, and trunk muscle coordination. These impairments may contribute to persistent symptoms and functional limitations.

Sensorimotor balance training has emerged as a rehabilitation approach aimed at improving sensory integration, neuromuscular control, and dynamic postural stability. Previous studies have reported beneficial effects of sensorimotor-focused interventions on pain and functional outcomes; however, most investigations have relied primarily on self-reported measures, with limited assessment of objective biomechanical changes.

The DIERS Formetric 4D system provides a non-invasive, radiation-free method for evaluating spinal posture and alignment, including measures of trunk imbalance, pelvic tilt, and sagittal spinal curvature. The integration of objective spinal assessment with rehabilitation interventions may provide greater insight into the relationship between symptom improvement and structural-functional adaptations.

This randomized controlled trial aims to evaluate the effects of sensorimotor balance training on pain intensity and spinal alignment in adults with chronic nonspecific low back pain. The study will compare sensorimotor balance training with standard physiotherapy and examine whether improvements in pain are associated with measurable changes in spinal alignment. Findings from this study may contribute to the development of evidence-based rehabilitation strategies for the management of chronic nonspecific low back pain.

Inclusion Criteria:

• Adults aged 18 to 59 years. Diagnosis of chronic nonspecific low back pain lasting at least 3 months. Pain intensity score of 4 or greater on the Numeric Pain Rating Scale (NPRS). Body Mass Index (BMI) between 25 and 35 kg/m². Ability to safely participate in the exercise program and comply with study procedures.

Exclusion Criteria:

• Acute low back injury. History of spinal surgery. Neurological disorders affecting movement or balance. Musculoskeletal disorders affecting movement or balance. Professional athletes. Individuals engaged in heavy manual labor. Any medical condition that would prevent safe participation in the intervention program.

A decision regarding the sharing of de-identified individual participant data (IPD) has not yet been made. The study consent form includes an option for participants to allow future use of their de-identified data for research purposes. Any future data-sharing arrangements will be considered after study completion in accordance with participant consent, ethical approvals, and institutional policies.

Outcome assessors will be blinded to participants' group assignments throughout the study to minimize assessment bias. Due to the nature of the physiotherapy interventions, participants and treating physiotherapists cannot be blinded to treatment allocation.