Osteoporosis is a disease of the skeleton characterized by low bone mass and microarchitectural deterioration, with a consequent increase in bone fragility and susceptibility to fracture.¹ It is defined and diagnosed by measurably low bone mineral density (BMD).² Primary osteoporosis in women occurs most often after menopause and is related largely to estrogen deficiency. The terms primary osteoporosis and postmenopausal osteoporosis are often used interchangeably.² Secondary osteoporosis can result from changes in bone health related to certain medications, such as glucocorticoids, antiepileptic drugs, cyclosporine, and heparin, and certain diseases and conditions, such as cystic fibrosis, rheumatoid arthritis, end-stage renal disease, hyperthyroidism and other thyroid abnormalities, amenorrhea, alcoholism, osteogenesis imperfecta, anorexia nervosa, and organ transplant.²

Bone substance is constantly turning over through balanced processes of bone formation and bone resorption. Normally, these processes occur in a tightly coupled fashion, resulting in little net change in bone mass.² Osteoporosis occurs when the rate of bone resorption is greater than the rate of bone formation. As bone mass diminishes, bones become fragile, raising the risk of fractures from even minimal trauma.^3,4 Clinical diagnosis of osteoporosis is based on BMD scores via dual energy X-ray absorptiometry (DXA) which can lead to fragility fractures.⁵ A fragility fracture is caused by an injury that would be insufficient to fracture normal bone – the result of reduced compressive and/or torsional strength of bone.⁶ In the clinical setting, a fragility fracture is often recognized as a fracture related to a fall from standing height or lower, or as the result of minimal or no identifiable trauma.⁷

More than 10 million women and men in the U.S. have osteoporosis, and 34 million more have low bone mass (osteopenia), placing them at increased risk for this disease.⁸ The World Health Organization estimates that up to 70% of women older than 80 have osteoporosis.⁹ Although osteoporosis strikes more women than men, both men and women lose bone mass at approximately the same rate by age 65 or 70. According to the National Osteoporosis Foundation, one in two women and one in eight men over the age of 50 in the U.S. will suffer an osteoporosis-related fracture in their lifetime. One study placed the annual estimated cost of 1.5 million fractures as high as $17 billion¹⁰ and rising. In fact, the National Center for Injury Prevention and Control has projected that cost could escalate to $240 billion by the year 2040.¹¹ As the median age of the population in the U.S. increases, osteoporosis will become a major health concern in almost every setting in which physical therapists work.¹²