Physical activity, muscle function, falls and fractures

Study design: A thematic review. Objectives: To evaluate if physical activity enhances muscle strength, improves balance, and reduces the fall frequency and the fracture incidence. Background: One of the major medical problems of today is the increasing incidence of fragility fractures. Muscle strength and fall is one of the major determinants of a fracture. If physical activity could increase muscle strength, improve balance and reduce the fall frequency, then training could be recommended as prevention for fractures. Methods: The review used Medline (Pub Med) and the search words exercise, physical activity, muscle, muscle strength, balance, falls, fractures Randomised controlled trials (RCT) were predominantly included, although this not is a systematic review. Results: The evidence that physical activity modifies the risk factors for fall is compelling, although RCT with fractures as end point are lacking. Physical activity is associated with improved muscle strength, co-ordination and balance. Physical training increases muscle strength also in octogenarians by up to 200 %, i.e. a much more pronounced effect than the corresponding increase in muscle volume or bone mass. There is also evidence that physical activity decrease the actual number of falls. Observational cohort and case-control studies imply that physical activity is associated with reduced hip fracture risk. If exercise reduces the number of vertebral fractures and other fragility fractures is less evaluated. Conclusions: Physical activity in older ages can be recommended to improve muscle strength and balance, to reduce the risk to fall and fractures, although the highest level of evidence - RCT with fracture as endpoint - is lacking. Keywords: exercise; muscle strength; muscle mass; fall; fractures; physical activity (Published online: 30 December 2008) Citation: Food & Nutrition Research 2008. DOI: 10.3402/fnr.v52i0.1920