Background: Low back pain (LBP) is a leading cause of disability worldwide. Mulligan's Sustained Natural Apophyseal Glides (SNAGs) are manual therapy techniques shown to reduce pain and improve function in LBP. However, whether applying SNAGs in loaded (weight-bearing) versus unloaded (non-weight-bearing) positions yields superior clinical outcomes remains unclear.

Objective: To compare the effects of lumbar SNAGs applied in loaded versus unloaded positions on pain, disability, and function in individuals with chronic non-specific LBP.

Methods: A randomized, single-blind, parallel-group clinical trial will recruit 34 participants with chronic LBP. Participants will be allocated to receive SNAGs in either loaded or unloaded positions, combined with a standardized exercise program, for 6 sessions over 1 week. The primary outcome is pain intensity (Numeric Pain Rating Scale) and lumbar flexion range of motion. Secondary outcomes include disability (Oswestry Disability Index). Outcomes will be measured at baseline and immediately post-treatment. Data will be analyzed using linear mixed models on an intention-to-treat basis.

Conclusion: This trial will determine whether a loaded SNAG application provides superior benefits compared to unloaded SNAG in the treatment of chronic LBP. Findings may guide clinical decision-making and optimize manual therapy application.

Inclusion Criteria:

• Chronic non specific low back pain for 6 weeks or more
• Who scored between three and six on a visual analogue scale (VAS)
• Restriction of the movement was only in flexion ROM

Exclusion Criteria:

• Pregnancy,
• Obese,
• Infectious conditions of the spine,
• Autoimmune disorders,
• Malignancy
• Any contraindication to physiotherapy and manual therapy
• Any patient received physical therapy sessions last 6 months

The project is funded by university of Hail and all the data should be authorized through it