Feeling your age? Maybe skip the ashtanga class.

A new Mayo Clinic study suggests that people with osteoporosis should avoid certain poses in yoga.

According to the study, published in Mayo Clinic Proceedings, yoga postures that flex the spine beyond its limits can increase the risk of compression fractures in people who already have thinning bones.

Osteoporosis is a disease in which bones lose density, making them more prone to breaks.

Mayo Clinic researchers reviewed the health records of 89 patients — mostly women, who are more susceptible to osteoporosis and related conditions — who were referred to the clinic for pain related to yoga practice.

The patients identified 12 poses that they said caused or aggravated their back, neck, shoulder, hip, or knee pain. The most common poses involved extreme flexing or extension of the spine.

According to the patients’ medical records, 29 had bone injuries, such as compression fractures, slippage of vertebrae, and degeneration of disks. The compression fractures in particular appeared to be related to yoga postures that put pressure on the vertebra and disks.

“Yoga has many benefits. It improves balance, flexibility, strength and is a good social activity,” said Dr. Mehrsheed Sinaki, a Mayo Clinic physical medicine and rehabilitation specialist and the study’s senior author. “But if you have osteoporosis or osteopenia, you should modify the postures to accommodate your condition. As people age, they can benefit by getting a review of their old exercise regimens to prevent unwanted consequences.”

Rochester Post-Bulletin