Specific and Shared Mechanisms Associated With Treatment for Chronic Neck Pain

Treatment mechanisms involve the steps or processes through which an intervention unfolds and produces the change in an outcome variable. In other words, a treatment mechanism is "how a treatment works". Treatment mechanisms can be specific to the intervention provided (i.e., fiber size increase and neuro adaptation occur with resistance exercise) or shared with other treatments (i.e., theoretically, increased therapeutic alliance and reduced fear of movement occur with almost all forms of interventions). In this proposal, the study team plans to investigate specific and shared treatment mechanisms of a manual therapy approach and a resistance exercise approach for treatment of chronic neck pain. The study team is targeting chronic neck pain because it is a common problem that is second only to low back pain for years lived with disability. Routinely, chronic neck pain management includes manual therapy and resistance exercise, as both approaches are included in clinical practice guidelines. The study plans to answer two research questions: 1) what are the specific mechanisms associated with manual therapy and resistance exercise interventions (and are these different), and 2) what are the shared mechanisms associated with these interventions, and do both mechanisms mediate clinical outcomes? The study team hypothesized that manual therapy and resistance exercise approaches will exhibit different specific treatment mechanisms. Further, the team hypothesizes that both approaches will lead to shared treatment mechanisms, which will notably influence outcomes at both 4 weeks and 6-month follow-up. This study is important because it will help identify how different treatment mechanisms influence clinical outcomes. There are several studies in the psychological literature that demonstrate the role of both specific and shared treatment mechanisms but this form of investigation is mostly absent for general musculoskeletal rehabilitation interventions. It will be the first study involving manual therapy in which specific and shared mechanisms are evaluated and explored against clinical outcomes.

Inclusion criteria

• Individuals with chronic neck pain (chronic pain is defined using the International Association of the Study of Pain (IASP) pragmatic criteria of pain lasting for 3 months or more that cannot be attributed to another diagnosis or condition.)
• 18 years of age and older
• experience ongoing neck pain of ≥3 on a 10-point scale for most days of the previous 3-months.

Exclusion criteria

• Individuals with cervical pain and suspected radicular symptoms
• a history of neck surgery within 1 year
• current or suspected red flags
• unable to speak or write in English.