Joint hypermobility is largely understood as a dysfunction of collagen fibers within the connective tissues of ligaments and tendons, allowing for a range of motion which is markedly increased over validated normal values. Generalized Joint Hypermobility (GJH) is defined using a Beighton score of ≥ 5/9. Additionally, previous studies have used microscopic imaging to determine these relationships, and there has yet to be a published study looking into the correlation between the sonographically determined length and width of ligaments, and GJH in a college-aged population in North America.
PURPOSE:
To determine the relationship between the length and width of the anterior bundle of the Ulnar Collateral Ligament (UCL) of the elbow and GJH.
METHODS:
Three hundred and thirty undergraduate students (age 19.24 ± 2.07 yrs) enrolled in A&P I classes completed the Beighton score, including measures of elbow hypermobility. Ultrasound images of the participants’ ulnar collateral ligament were obtained in both arms under a gravity induced valgus force in supine.
RESULTS:
Overall, 48 of 330 participants (14.6%) reported generalized joint hypermobility (GJH) based on a Beighton score ≥ 5. Sixty-three participants reported hypermobility in at least one elbow; there was no difference in prevalence of hypermobility between elbows (Right: r = .483, p < .001; Left: r = .465, p < .001). Hypermobility in one elbow was strongly correlated with hypermobility in both elbows (r =.828; p < .001). We found moderate correlations between UCL thickness and joint gapping for left and right elbows (r=.422,r=.324,p < .001)
We found no difference in UCL thickness or joint width between participants with hypermobile elbows and those without (e.g., right elbow joint width under valgus stress: Normal = .231799, Hypermobile = .228415; t(251) = .301, p=.763) Left elbow joint width under valgus stress was weakly correlated (r =.167, p=.006) with GJH overall but not specifically with left elbow hypermobility.
CONCLUSION:
There was no relationship between Beighton score and UCL anterior bundle thickness or joint width under gravity induced valgus stress. There was no statistically significant difference in UCL thickness or joint width in participants with elbow hypermobility and those without.