Effects of physical activity on postural stability.

Fall-induced injuries are increasing more rapidly than demographic changes can account for [1]. The potential effects of a fall include not only injury or death but also fear of further falls (which limits activity and makes the situation worse), depression and other psychological sequelae [2]. The scientific evidence regarding the role physical activity has to play in falls management is confusing and inconsistent. Physical activity and exercise have been identified as major factors that influence the risk of falls and fractures among older adults. Physical activity describes any body movement that substantially increases energy expenditure. It is commonly divided into occupational and leisure activity. Physical activity can range from everyday actions (e.g. walking, heavy housework and gardening) or leisure activities such as swimming, dancing, cycling or sporting and exercise opportunities provided in gyms and fitness centres. Whereas exercise is used to describe planned and structured activities where repetitive body movements are made to improve or maintain components of fitness (e.g. strength training or a fitness programme designed to improve cardiovascular risk or reduce falls). Accumulating evidence indicates that physical activity and structured exercise help maintain an independent life by maintaining postural stability (balance), strength, endurance, bone density and functional ability and, in so doing, may prevent falls and injuries associated with falls in older age (Figure 1). But some types and patterns of physical activity or exercise do not seem to improve postural stability, let alone prevent or reduce the risk of falls. Indeed, some activities seem to increase the risk of falls, either by increasing exposure to risky environmental conditions (slippery or uneven floors, cluttered areas, bad pavements), acute fatigue, or unsafe practice (Figure 1). There have been calls for advice on prevention and treatment initiatives in relation to falls and fallrelated injuries and for evidence of effectiveness, or models of practice [3]. This paper reviews the scientific evidence regarding the role that physical activity has to play.