The study group included 147 Caucasian girls with IS, aged 9-18 years (mean 13.6 ±2.2), Cobb angle range 11°-65°, mean 27.9 ±11.9, comprising 42 single thoracic, 31 single lumbar and 74 double curve scoliosis. According to the Cobb angle, there were 70 mild (10-24º), 54 moderate (25-40º) and 23 severe (> 45º) curves. The control group included 147 girls aged 9-18 years (mean 13.1 ±.3), selected at random from the group of 300 girls free of IS (angle of trunk rotation <5°). The presence of JH was assessed with the 9-point Beighton scale [1], using the cut-off ≥5 points.