I find it fascinating that weight baring exercises, yoga included, can reverse the effects of these conditions.
In a Livestrong article titled, Osteopenia & Yoga, Loren Fishman, physician, author and creator of the website Sciatica.org, has conducted research on the benefits of yoga for osteopenia and osteoporosis. … According to his research, yoga improved both bone mineral density and bone strength, compared to subjects not participating in yoga.
Baxter said research shows that we can stimulate new bone growth along the lines of stress by holding poses (weight baring pose) between 8-72 seconds.
Baxter wrote on his blog Yoga for Healthy Aging, that engaging opposing muscle groups while doing a pose like Downward Facing Dog increases the stimulation of the underlying bone cells that make new bone.
From the Livestrong article, seated postures can benefit the hip; examples include Hero pose, Bound Angle pose and Wide Angle pose. Standing poses put weight on the legs and hips, which help strengthen the bones in these areas; examples include Mountain pose, Triangle pose, Warrior pose and Side Angle pose.