The goal of this randomized controlled trial is to compare the effectiveness of lumbar stabilization exercises and muscular chain therapy on reducing pain intensity and functional disability in patients with mechanical CLBP.

• Participants will be randomly assigned to two groups:
• Group A: Lumbar stabilization exercises
• Group B: Muscular chain therapy (posterior sagittal muscle chain)

Outcomes will be assessed at baseline and on week 6 to evaluate which exercise program is more effective in reducing pain and improving functional outcomes.

Inclusion Criteria:

• Patients aged between 18-30 years will be included in the study.
• Participants must have a history of mechanical CLBP.
• The pain must be localized to the lumbar region.
• Participants must be able to perform physical activities and participate in exercise-based interventions.
• Participants who have pain range > 4 will be included in the study.

Exclusion Criteria:

• Patient with structural lesions, such as spondylolisthesis, stenosis, vertebral bone fracture, scoliosis and kyphosis on x-ray, will be excluded.
• Pregnant females would be excluded.
• Females with a history of neurological, infections, and systemic disease, including cerebrovascular disease, spondylitis, cancer, spinal cord disease, cauda equine, rheumatologic disorders.
• Females who have undergone spinal surgery or any surgical intervention related to the lower back or pelvis will be excluded.
• Lumbar radiculopathy will be excluded in the study.

This randomized controlled trial was double-blinded. Participants were randomly assigned to either the lumbar Stabilization Exercise group or the muscular chain therapy group using a simple randomization (lottery) method.

Participants were informed that both interventions were effective physiotherapy treatments for chronic low back pain but were not told which group they belonged to. The outcome assessor, who had over fifteen years of experience, remained blinded to group allocation throughout data collection at baseline and week 6.

To maintain blinding, participants were instructed not to disclose their exercise details during assessment, and all data were recorded using coded identifiers (Group A or B).