The 'rotational preconstraint'.

This model provides a novel view of the etiology of some scolioses and can answer some of the biomechanical questions regarding pathogenesis of dorsal curves. According to our findings, paravertebral muscular imbalance is likely to favour such a pathological condition which, with the interference of the postural reflexes and the body weight-related vertical loading, might lead to the formation of a true scoliotic curve. Review of earlier research studies in the light of our findings reveals controversy in some authors' reported results and their own interpretations and seems to generally support our theory. Copyright 2000 Harcourt Publishers Ltd.