That pain in your lower back may not be caused by sprains or strains, sleeping on a saggy mattress or just the wear and tear of life. If you’re a woman in midlife or older, your aching back may be set off by menopause.

Background: Women don’t have exclusive rights to lower back pain. It’s quite common in men, too. The cause is often degeneration of the rubbery, cushioning discs in the lumbar region of the lower back—and it tends to gets worse as we get older. But some studies have also found that estrogen helps keep these discs in good shape and that the loss of estrogen that comes with menopause can weaken discs. So researchers set out to learn more about how menopause affects this common cause of back pain in women.

Study: Researchers from China used MRI images, rather than simple x-rays, to evaluate disc degeneration in 1,566 women and 1,382 men of similar ages with low back pain. None of the women were taking hormone therapy. The women ranged in age from 30 to 93—some were premenopausal, others perimenopausal and many postmenopausal. Average age at menopause—defined as one year after the last menstrual period—was 51, and the average age of women in the study was 68. The researchers used an eight-point grading system to identify the level of lumbar disc degeneration.

Results: Postmenopausal women had significantly more severe disc degeneration than age-matched men. A serious level of degeneration (grade five or above) was found in 61% of postmenopausal women but only 42% of men the same age.

Surprising finding: Before menopause, women had less disc degeneration than men of the same age. Researchers believe one reason is that women tend to experience less mechanical stress and physical injury in their jobs. But around the ages of 50 to 60, the discs of women began to degenerate much more quickly than those of men. It didn’t happen all at once—the discs of postmenopausal women degenerated progressively throughout the first 15 years after menopause. After 15 years, disc degeneration in women slowed down and kept pace with degeneration in men.

Bottom line: You are now free to blame menopause for your aching back. But you’re not helpless. Now is the time to strengthen the muscles that support your spine—that can take pressure off your lumbar discs. Consider this yoga program, which helps with strength and balance—and also strengthens bone and helps prevent and even treat osteoporosis. If your back already hurts, consider these 15 ways to ease back pain.