Mechanical stimuli and bone health: what is the evidence?

PURPOSE OF REVIEWWith the recent emergence of associations of bisphosphonate therapy with atypical fractures and osteonecrosis of the jaw, there is renewed interest among clinicians and patients for nonpharmacological approaches to bone health. Here, we review the new studies published in the past year or two that advance our knowledge of the effect of mechanical stimuli on bone health. RECENT FINDINGSPhysical activity is associated with serum sclerostin levels; the most physically active individuals have the lowest serum sclerostin levels. Observational trials suggest that physical activity participation results in higher bone mass, but clinical trials suggest that the effects of exercise on areal bone mineral density are small, and vary with the site measured and the type of exercise. Based on current data, it may be best to combine progressive resistance training with interventions such as walking or aerobic dancing if the desire is to improve both spine and hip in postmenopausal women. Low-magnitude high-frequency whole body vibration does not improve bone mineral density and bone structure in postmenopausal women. SUMMARYPhysical activity and exercise are important for the maintenance of musculoskeletal health as we age. Future studies need to investigate the effects of exercise in older populations with rheumatological diseases and those with a history of fragility fractures.