Patients with juvenile onset fibromyalgia and joint hypermobility demonstrated poorer overall functioning compared with those without joint hypermobility.
Patients with juvenile onset fibromyalgia (JFM) and joint hypermobility exhibited small but noticeable differences in biomechanics compared with those without joint hypermobility while performing a landing and jumping exercise, according to a study published in BMC Pediatrics.1 Decreased joint stiffness during landing has been linked to decreased joint stability and increased joint laxity, which may increase the risk for injury in this patient population.
Joint hypermobility, defined as excessive range of movement, has been linked to chronic pain, impaired physical functioning, and hindered physical activity. It is common in pediatric patients with hereditary connective tissue disorders, as 40% of patients with idiopathic chronic musculoskeletal pain musculoskeletal pain conditions, including JFM, are diagnosed with Hypermobility Spectrum Disorder (previously referred to as Joint Hypermobility Syndrome).2
“This study has the potential to advance our understanding of potential sub-groups of patients which widespread musculoskeletal pain, such as those with joint hypermobility, and potential clinical implications of this co-occurring condition,” wrote lead investigator William R Black, PhD, pediatric psychologist and assistant professor in the Department of Pediatrics, University of Kansas School of Medicine, and colleagues.
Investigators analyzed whether adolescent patients (aged 12 to 18 years) with JFM and joint hypermobility had differences regarding pain, biomechanics, and daily functioning compared with those without joint hypermobility while performing a moderately vigorous functional task, the drop vertical jump (DVJ). Joint hypermobility was determined using the Beighton Score and pain intensity was measured using the Visual Analog Scale (VAS). Subjects were enrolled from a larger randomized pilot trial of adolescent patients with JFM.
Of the total sample of patients (n = 36), 13 (36.1%) adolescents exhibited joint hypermobility and 23 did not meet the diagnostic criteria for the condition. As functional disability increased, Beighton scores decreased, indicating increased scores were related to better physical function.
Patients with JFM and joint hypermobility demonstrated poorer overall functioning (mean deviation [Md] = 20 vs Md = 29, respectively); however, there were no differences in pain between groups (Md = 6.45 vs Md = 6.9, respectively).
The qualitative visual evaluation indicated patients with joint hypermobility demonstrated increased hip flexion throughout the DVJ task. Additionally, subjects with joint hypermobility had decreased hip frontal plane hip abduction movement during the landing phase, defined as “early stance,” and greater hip and knee transverse plane moments during the propulsion phase, labeled the “late stance,” of the DVJ. There were no differences in the lower extremity biomechanics between cohorts.
Investigators stated the pilot study was limited by the small number of patients, which may not have been able to accurately detect significant differences between the groups. Additionally, results may not be generalizable to other chronic musculoskeletal pain conditions or patients with joint hypermobility who do not have chronic pain. Lastly, joint hypermobility was based on Beighton scores, which do not capture joint laxity in other important areas of the body related to strength assessments, such as the hips and the internal/external rotation of the knees. Future research should focus on enrolling a larger sample size to determine whether biomechanical differences in patients with joint hypermobility could affect the response to physical therapy or exercise programs.
“These results tentatively support the use of neuromuscular training and exercise programming in adolescents with chronic musculoskeletal pain, regardless of joint hypermobility status; though, additional work is needed to address concerns regarding our study findings being attributed to error alone,” investigators concluded.