LEFT-HANDEDNESS AND RISK OF THORACIC HYPERKYPHOSIS IN PREPUBERTAL SCHOOLCHILDREN

Background. Hand dominance and spinal posture were studied for their p rediction of the development of thoracic hyperkyphosis during the pube rtal growth spurt. Methods. The cohort consisted of all the fourth-gra de school children of the Western School District of Helsinki, Finland , in the spring of 1986. They were examined annually from the mean age of 10.8 to 13.8 years. Handedness was determined at the baseline exam ination by observing the hand with which the child was writing. Anthro pometric measurements, posture and growth were followed-up annually. A lateral standing radiograph was undertaken in those children who had pronounced thoracic kyphosis in spinal pantography. Kyphotic angles gr eater than or equal to 45 degrees were considered hyperkyphotic. Resul ts. In both girls and boys, left handedness was found to be a powerful determinant of hyperkyphosis. In left handed children the odds ratio (OR), adjusted for baseline spinal measurements, was 4.11 (95% confide nce interval [CI] : 1.39-12.13). Hump size measured by the forward ben ding test also predicted significantly the development of thoracic hyp erkyphosis (OR = 1.48; 95% CI : 1.23-1.76, per one degree). Conclusion s. Left handedness may be a risk factor for thoracic hyperkyphosis dur ing the pubertal growth spurt.