Pilot Study for Use of an Arthrometer to Assess Joint Laxity in People with Ehlers-Danlos Syndrome

Purpose: Joint hypermobility is a condition in which synovial joints move beyond normal limits. Approximately 10-25% of children and 5-25% of adults experience hypermobility syndrome. One such hypermobility syndrome is an inherited connective tissue disorder known as Ehlers-Danlos Syndrome (EDS). Typically, a score of 4-5 out of 9 on the Beighton scale is indicative of hypermobility in adults. Whereas 6 out of 9 is the criteria for children. No significant correlations were found between the systemic features of EDS and the Beighton score. The purpose of this pilot study was to see if an arthrometer could be used to provide quantitative values of joint laxity to differentiate between individuals diagnosed with Ehlers-Danlos Syndrome versus controls. Methods: A Mobil-Aider arthrometer was used to quantify anterior and inferior translation of the glenohumeral joint and anterior translation of the talocrural joint. Results: Thirteen control participants without EDS and 14 participants diagnosed by a physician with EDS participated. Significant between-group differences and medium to large effect sizes were found for all 3 motions. Conclusions: The Beighton score has known limitations as diagnostic criteria for hypermobility syndrome and EDS. Testing with an arthrometer may contribute objective data on the magnitude of hypermobility, not just dichotomous criteria. This clinical data may contribute to the clinical assessment of connective tissue disorders.