Childcare in nursery schools has been shown to be associated with an elevated prevalence of neck, shoulder, arm and low back disorders. The current evidence suggests that exercises seem to be the only effective preventive intervention. Thus the purpose of this study is to determine the effectiveness of an extension-oriented exercise program in preventing low back/neck pain and functional disability in nursery school teachers. In addition, the investigators also sought to identify the occurrence of musculoskeletal complaints in this category of workers.