Osteoporosis is a systemic disease in which bones become fragile and more likely to break. It can progress painlessly until the point of fracture if left untreated. Essentially the body starts to lose bone faster than it makes bone. A bone density or DEXA scan defines osteoporosis as a t-score of less than or equal to -2.5 below the standard deviation. Osteopenia is the early stages of bone loss and is measured as a t-score of -1.0 to -2.5 below the standard deviation.(1)
The numbers tell us that 44 million people or 55 percent of the people aged 50 and older in the US have either osteoporosis or low bone mass. The International Osteoporosis Foundation reports that 1 in 3 women over the age of 50 and 1 in 5 men over the age of 50 will experience an osteoporotic fracture during their lifetime. Unfortunately a prior fracture is associated with an 86% increased risk of another fracture. The inherent risk of osteoporosis is a fracture.(2)
So how do we build bone in the first place? There are a group of cells responsible for building new bone and cleaning up bone as it breaks down. It is a constant give and take. To build bone we need to stimulate cells called osteocytes. Once activated the osteocyte will pull calcium and phosphorus from the blood stream to build bone. These cells respond to pressure, stress and strain. Within the osteocyte there are osteoblasts that are responsible for building new bone. I like to call them the construction workers. Another cell, called osteoclasts are responsible for breaking down bone and cleaning up old and/or broken bone. I like to call them the janitors.(3)
The loss of bone density can be caused by genetic, hormonal, metabolic and nutritional factors.(2) Normally we build bone until around the age of 30. Then the rate of breaking down bone begins to speed up and the rate at which we build bone slows down, meaning we can start to see more osteoclasts than osteoblasts. This is where exercise including yoga can help.
Wolff’s law tells us that the architectonic of bone follows the line of force to which bone is exposed, meaning that bone grows to resist the forces we put through them. The pressure outside the cell turns into electrical energy which creates a molecular change inside the cell. It works into the nucleus of the cell and changes the DNA of the cell. The forces stimulate the osteocytes and osteoblasts to build new bone. Research tells us that we need to maintain a deforming force for 12-72 sec to stimulate the osteocytes (greater than 72 sec cells go into a refractory period). The force can be compression, torsion or a tensile force.(3,4)
With exercise like yoga we can use gravity and our muscles to create the forces needed to stimulate new bone growth by holding the poses for the suggested 12-72 seconds. Dr. Loren Fishman (www.sciatica.org) and his team have studied 12 poses and found that yoga was a safe and effective means to reverse bone loss in the spine and femur (upper leg bone).(5) He continues to study more yoga poses and their effects on bone density. I teach these poses and more in my Yoga vs Osteoporosis Workshops and classes.
1. Osteoporosis and Musculoskeletal Disorders. National Osteoporosis Foundation. https://www.iofbonehealth.org/. 2017.
2. Data & Publications. International Osteoporosis Foundation. https://www.iofbonehealth.org/. 2017
3. Fishman L, Saltenstall E. Yoga for Osteoporosis [PowerPoint]. YogaUOnline. 2016.
4. Frost HM1. Wolff’s law and bone’s structural adaptations to mechanical usage: an overview for clinicians. Angle Orthod. 1994;64(3):175-88.
5. Lu Y, Rosner B, Chang G, Fishman L. Twelve-Minute Daily Yoga Regimen Reverses Osteoporotic Bone Loss. Topic in Geriatric Rehabilitation. 2016;32(2):81-87.