Spine Extension for Bone Health

Osteoporosis is a common bone condition that results from a decrease in bone density. It can be diagnosed by a bone mineral density scan, a special type of x-ray procedure, or based on a clinical finding of a fragility fracture which is defined as a bone fracture that occurs with a relatively small force, such as breaking the femur, a leg bone, from stumbling on a rug.

Osteoporosis is a devastating disease because it is clinically silent, completely painless until the weakened bone unexpectedly fractures. The most common site of fracture is in the small bones of the spine, called a vertebral compression fracture. While it has long been known that exercise plays a key role in supporting bone health, one study especially stood out in illustrating how effective spinal extension exercises can be.

Mehrsheed Sinaki, a physician and researcher with a specialty in physical medicine and rehabilitation, published a 2002 randomized-controlled trial entitled Stronger Back Muscles Reduce the Incidence of Vertebral Fractures: A Prospective 10-year follow-up of Postmenopausal Women. The overall finding is that women who perform daily spine exercises for two years showed retained strength eight years later compared with women in the control group. Here are some fascinating details about the study:

  • The benefit of the exercise was sustained years after the women stopped performing them. The women in the intervention group performed daily extension exercises for the first two years of the study. Almost all of them stopped performing these exercises for the next eight years before the ten-year follow-up measurements were taken. Nevertheless, the women in the intervention group demonstrated more back strength and less vertebral fractures all those years later.
  • The prescribed exercise was very short. I thought that, because the benefit was large, the prescribed exercise regimen must have been complex, consisting of multiple different exercises and taking a significant time investment. In fact, the exercise required one set of ten spine extensions.
  • The prescribed exercise was very simple. The patients lay prone (on the stomach) and extended (arched the back) their back. In patients who could tolerate it, a small backpack with weights was added, with no more than 50 pounds allowed. In summary, the patients were arching their back ten times with a small backpack filled with weights.
  • The benefit was large in the short and long-term. There was a clear long-term protective effect. The back-exercise group increased their strength from 39.4kg at baseline to 66.8kg at 2 years; at ten years, after eight years without back exercise, the strength was 32.9kg. By contrast, the control group’s strength at the ten-year follow-up was 26.9kg despite starting with a similar baseline. The risk of compression fracture was almost three times greater in the control group.