Mechanisms and Modulation of Pain Modulatory Capacity

Many physiological systems (bioenergy, immune etc.) involve feedback mechanisms to respond to challenges, with increased output or capacity for adaptive change. A similar process is plausible for pain modulation where previous successful pain experience and resolution suggests a pain modulatory system with adaptive capacity. The proposed research examines how a musculoskeletal training program modulates pain response in people with fibromyalgia compared to healthy individuals. Previous research suggests that moderate-high level exercise is associated with attenuation of pain sensitivity and clinical pain intensity in healthy individuals. The proposal seeks to extend findings from previous research and examine how repeated exposure and subsequent adaptations to musculoskeletal pain over time influence pain modulation (PMC). The first outcome is that people with fibromyalgia (FM) will have PMC trainability similar to asymptomatic controls, with the obvious implications for clinical application. The second outcome is that FM patients will demonstrate a deficit in PMC trainability. This outcome will represent an important diagnostic sign, and guide research to additional mechanistic investigation. The third outcome is that impaired or lessened PMC trainability is evident in FM patients and this variability can be explored as an individual difference with clinical implications. The theoretical fourth potential outcome is sensitization in FM patients, however pilot data show that DOMS resolves within the same relative time window as controls. Though not hypothesized, the data and design will allow for examination of this possibility. One potential conclusion from these projects could be that FM arises from an inability to enter a recovery period within which PMC could adapt and increase resilience. The proposal will be able to address at least some of the potential for this inability to recover.