The main purpose of this study is to identify short-term predictors of positive responses to a spinal manipulation treatment. To do this, positive responses to treatment, characterized by improvement in pain score, functional capacity, as well as the global perceived change will be evaluated using single and multiple logistic regressions in which biomechanical variables, comfort, expectation will used as potential predictors.

The main purpose of this study is to identify short-term predictors of positive responses to a spinal manipulation treatment. To do this, positive responses to treatment, characterized by improvement in pain score, functional capacity, as well as the global perceived change will be evaluated at baseline and at 7 days. Pain score will be also assessed every day with text-tracking. Global perceived change will be evaluated using single and multiple logistic regressions in which biomechanical variables, comfort, expectation will used as potential predictors. 100 individuals with a history of non-specific back pain will be recruited in a chiropractic care center.

Inclusion Criteria:

• Being aged over 18 years old
• Presenting non-specific back pain (chronic >=3 months or recurrent complaint)
• Speaking French or English

Exclusion Criteria:

• Symptomatic thoracic pain
• Non-musculoskeletal disorders pain
• Pregnancy
• Not eligible to spinal manipulation (if osteoporosis, vertebral fracture history, thoracic disk herniation)

Participants are patient in the chiropractic care center