Juvenile fibromyalgia (JFM) affects up to six percent of the adolescent population and results in chronic, widespread pain, functional disability, and poor quality of life that often persists for years. Generalized joint hypermobility is common among adolescents with JFM and is also associated with widespread joint pain and many similar symptoms of JFM. Both adolescents with JFM and generalized joint hypermobility demonstrated altered biomechanics which may contribute to pain exacerbation. Despite the association between JFM and generalized joint hypermobility, it is unknown if joint hypermobility exacerbates symptoms and influences response to treatment in this cohort. Preliminary evidence suggests cognitive behavioral therapy (CBT) and neuromuscular training (NMT) are effective in reducing pain and functional disability in this cohort; however, NMT has been shown to be differentially effective to individuals who demonstrate faulty biomechanics. A better understanding of factors, such as joint hypermobility, that influence symptom exacerbation and response to treatment will aid in the development of targeted interventions and hopefully improve outcomes for adolescents with JFM.
Therefore, the purpose of this dissertation was to provide a comprehensive exploration of the influence of generalized joint hypermobility on the clinical symptoms, physical function, and response to intervention in adolescents with JFM. The goals of this study were 1) to compare baseline pain, functional disability, strength, and biomechanics between hypermobile and non-hypermobile adolescents with JFM, 2) compare baseline pain, functional disability, strength, and biomechanics between hypermobile adolescents with JFM and healthy adolescents with generalized joint hypermobility, and 3) compare response to treatment between hypermobile and non-hypermobile adolescents with JFM.
As part of a secondary analysis of a pilot randomized controlled trial, adolescents with JFM were categorized as hypermobile or non-hypermobile and baseline subjective pain, functional disability, lower extremity strength, and lower extremity gait biomechanics were compared between groups. Baseline subjective pain, functional disability, lower extremity strength, and gait and jump landing biomechanics were then compared between hypermobile adolescents with JFM and healthy adolescents with generalized joint hypermobility. Finally, pre- to post-intervention changes in subjective pain, functional disability, strength, and gait and jump landing biomechanics were compared between hypermobile and non-hypermobile adolescents with JFM, following completion of sixteen combined CBT and NMT sessions.
Although there were no differences in subjective pain, functional disability, or strength between hypermobile and non-hypermobile adolescents with JFM, hypermobile adolescents with JFM did demonstrate greater peak knee extension and lower peak ankle eversion during the stance phase of gait. Hypermobile adolescents with JFM also reported greater pain and functional disability and demonstrated greater lower extremity strength, lower knee extension moments during gait, and greater knee abduction angles during jump landing than healthy adolescents with generalized joint hypermobility. Comparison of response to treatment between hypermobile and non-hypermobile adolescents with JFM indicated there was no difference in change in pain, functional disability, strength, or biomechanics between groups. This information adds to our understanding of the presentation of JFM and the influence of generalized joint hypermobility in this cohort. While joint hypermobility may not influence subjective pain and functional disability, it does appear to influence movement patterns in adolescents with JFM, establishing groundwork for future research to explore the correlation between these movement variations and symptoms in adolescents with JFM.