Osteoporosis issue needs addition of extension exercise findings.

To the Editor: Thanks to the JAOA for the concise January 2000 supplement on osteoporosis. One small addition that would be especially relevant to osteopathic practice is specific inclusion of upper back extension exercises in the management of osteoporosis. Loss of height, the most clinically available indicator of osteoporotic vertebral wedging and compression fractures, is preceded by loss of compliance in connective tissues of the spine and rib cage. In women with osteoporosis, thoracic kyphosis is associated with loss of rib cage mobility, and decreases in vital capacity, inspiratory capacity, and total lung capacity.1, 2 Itoi and Sinaki3 studied the effect of back extensor strengthening exercises on posture in a group of 60 healthy, nonsmoking, estrogen-deficient women with an average age of 59 years. None of these women was receiving calcium, vitamin D, or estrogen supplementation, and none had had recent back pain or injury. The group of women was divided into a control group and an exercise group that practiced a weighted, prone back extensor exercise 10 times a day for 5 days a week. After 2 years, the measured thoracic kyphosis in spinal x-rays was compared with the kyphosis in the x-rays taken at the onset of the study. Among the subjects with substantial thoracic kyphosis at the onset of the study, those with significant increase in back extensor strength had a significant decrease in thoracic kyphosis of -2.8° + 4.2°, P + 0.041. Ten years before, Sinaki and Mikkelson4 studied 59 women with postmenopausal osteoporosis and back pain over a 2-year period. They divided the women into 4 groups, with 25 subjects receiving instruction in back extension exercises (E), 19 receiving extension and flexion exercises (E + F), 9 receiving flexion exercises (F) only, and 6 controls who received no instruction (N). They evaluated spinal x-rays for compression fractures and increased wedging before and after the study. The incidence of additional fractures was 89% in the F group, 67% in the N group, 53% in the E + F group, and 16% in the E group. They did not control for calcium, vitamin D, or estrogen intake. The authors concluded that pure flexion exercises resulted in more compression fractures and that extension or isometric exercises were more appropriate for women with significant postmenopausal osteoporosis. In the context of a coherent approach to the management of osteoporosis, we can expect that timely introduction of upper back extension exercises will improve kyphosis and respiratory efficiency as well as reduce incidence of compression fractures. Again, thanks for a wonderful issue.