An exaggerated thoracic kyphosis is physically disfiguring and a physiological and psychological consequence of declining bone mass. Previous investigators have correlated trunk strength and kyphosis, but have not demonstrated an exercise program effective at reducing the index of kyphosis. The purpose of this study was to determine the effect of trunk and scapular strengthening exercises on I/K, trunk and lower trapezius muscle performance, shoulder flexation range of motion (ROM) and self-perceived functional disability in postmenopausal women with low bone mass. Thirty-three postmenopausal women with low bone mass and a “clinically apparent” index of kyphosis were randomly allocated to 1 of 2 groups. Subjects in the control group continued their usual routine while subjects in the experimental group received a supervised program of 9 progressive trunk-strengthening exercises 3 times a week within 12 weeks. I/K was calculated from flexicurve measures. Trunk extensor and lower trapezius muscle performances were measured in gravity-minimized positions using a hand-held dynamometer. Shoulder flexion was measured with a goniometer. Functional disability was measured using the activities of daily living (ADL) component score from the Osteoporosis Functional Disability Questionnaire (OFDQ). Measurements were taken prior to and following the intervention by an examiner blinded to group assignment. The design was a prospective randomized controlled trial. Multivariate analyses of covariance (MANCOVA), using pre-treatment trunk strength, shoulder ROM and I/K as covariates, was used to test post-treatment differences between the groups. Between group differences in ADL scores were tested using the Mann Whitney U. The overall MANCOVA demonstrated a difference between groups and follow-up analysis revealed significant increases in shoulder flexion and muscle performances while decreasing the I/K. The Mann Whitney test demonstrated an increase in ADL scores in the treatment group. Clinical improvements in the exercise group compared to the control group ranged from 4 to 28% with a 12% decrease in the I/K. A 24-session, supervised program of progressive trunk strengthening exercises can reduce thoracic kyphosis and increase shoulder flexion, trunk muscle performance, and ADL in postmenopausal women with low bone mass.
