Program remains effective years after completion
A recent study conducted by The Mayo Clinic in Rochester, MN, has shown that a back-strengthening program not only can provide long-lasting protection against spinal fractures in women at risk for osteoporosis, but also that women who participated in the program retained a significant advantage in back strength even eight years after the program ended.1
Even though the program involved postmenopausal women who were between the ages of 48 and 65 when the study began, the implications of its findings may be much broader. When asked if back strengthening for even younger women would help prevent injuries later in life, Mehrsheed Sinaki, MD, lead author of the study, replied: "I should say yes. Just from this study, we can say that having a stronger back helps it to be less injured at whatever age."
It is very important for working women to have strong backs, she continues. "Strengthening those back muscles is very import to prevent injuries at the job," she says. "Being de-conditioned contributes to work-related injuries, even falls." Sinaki notes that 50% of white women (the group studied) experience a decrease in bone mass as they age, and one in four can develop fractures. "Nonwhites [have fewer fractures] because they have such good bone density, but not as many studies have been done," she adds.
Results are impressive
The study involved 50 postmenopausal women, 27 of whom performed "progressive, resistive back-strengthening exercises" for a period of two years. The other 23 served as the control group. Baseline measurements were taken for bone mineral density, back-extensor strength, biochemical marker values, level of physical activity, and spine radiographs.
The difference between the two groups in mean back extensor strength and bone mineral density, which favored the exercise group after completion of the program, were still statistically significant 10 years after the program was completed. The relative risk for compression fracture was 2.7 times greater in the control group than in the back exercise group. The control group actually increased the amount of exercise it had during the study period as well, making the results even more impressive. "The control group didn’t want to be left behind, so they did more exercise," Sinaki explains. "However, they didn’t necessarily do back exercises."
"To our knowledge," the authors wrote, "This is the first study reported in the literature demonstrating the long-term effects of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women."
Both groups experienced similar bone loss during the follow-up period. So why did the exercise group have a lower risk of fractures? "Because their muscles were stronger," Sinaki explains. "Stronger muscles will protect the bones even with bone loss."
Key to a good program
Clearly there is not just a single exercise program that will help build back strength, but there are key elements, she says. "You need to strengthen the back extensor muscles," she says, "And of course, the tummy, but those extensor muscles are major. There are some machines in the gym that you can use to push against those muscles, and isometrics are not bad, either."
At what age can women begin to show the effects of osteoporosis, to the point where it might threaten their health and productivity? "It’s really hard to say, but in general when they experience perimenopause, sometime from 45 on, and usually by 48-52," says Sinaki. "That’s when you can begin to lose bone mass, and the age at which you need to be watched, especially if you do a lot of heavy lifting."
The biggest challenge in implementing a successful back-strengthening program, she says, is compliance. "I have tried different things [to increase compliance], but for me what works best is to show the employees how interested you are in their health, and to tell them the reasons that these exercises are so important. You should also tell them how much more likely they are to be injured if they’re not in good health."
[For more information, contact: Mehrsheed Sinaki, MD, The Mayo Clinic, 200 First St. S.W. East 10, Physical Therapy, Rochester, MN 55905. Telephone: (507) 284-4904.]
1. Sinaki M, Itoi E, Wahner HW, et al. Stronger back muscles reduce the incidence of vertebral fractures: A prospective 10-year follow-up of postmenopausal women. Bone 2002; 30:836-841.