The relation of joint laxity and trunk rotation.

A study was designed to evaluate the joint laxity during scoliosis screening, and to show if there is a relation of joint laxity values to the trunk rotation. One thousand, two hundred and seventy-three children (598 females, 675 males) with an average age of 10.4 years were screened with a scoliometer and forward bending for trunk rotations. Scapular and shoulder elevations, flexible pes planus were recorded and joint laxity was evaluated with the Beighton score. There was high inter-observer and intra-observer reliability for both scoliometer and Beighton scores. In 41 children (3.2%) with Beighton score 7 or higher, trunk rotation measurements were higher than for the rest of the children. Trunk rotation measurements of 7 degrees or higher were found in 30 children, who were more lax than the rest of the group and were invited for radiography, with a detection of curves between 11 and 18 degrees in 10 of them. The Beighton score is a practical and reliable method for defining joint laxity. Although the number of patients with scoliosis was limited, there are findings supporting the relation between joint laxity and scoliosis. Moreover, there was increased laxity in children with increased trunk rotations. Ligamentous laxity may be one of the causes changing the contour of the back.