Intervention to Enhance Lateral Balance Function and Prevent Falls in Aging

Overview

Falls and their consequences are among the major problems in the medical care of older individuals. The long-term goal of this research is to establish the efficacy of a scientifically grounded and mechanism-based therapeutic intervention for improving balance function and preventing falls in older people. When human balance is challenged, protective stepping is a vital strategy for preventing a fall during activities of daily life. Many older people at risk for falls have particular difficulties with successfully stepping sideways as a protective response to loss of balance in the lateral direction. We propose that age-related declines in lateral balance function through impaired protective stepping that precipitates falls, result from neuromechanical (NM) limitations in hip abductor-adductor (AB-AD) muscle strength (torque and power). Moreover, we hypothesize that these functional and NM impairments are reversible with combined high intensity induced step training (IST) and muscle strengthening.

Falls and their consequences are among the major problems in the medical care of older individuals. Some 30 percent of community dwelling people aged 65 years and older, and over 50 percent of those living in institutions fall each year. Among older adults, complications of falls are the leading cause of deaths due to injury and are the most common cause of nonfatal injuries and hospitalization for trauma. The total lifetime healthcare cost of fall-related injuries for the elderly have been projected to reach $85 billion by the year 2020. Even in the absence of injury due to falling, the tendency to lose balance among the elderly commonly results in an overall reduction in the level of physical activity, and to a decreased ability to satisfactorily function in social roles. Despite the contributions of multiple risk factors to age-related falls (e.g., environmental hazards, orthostatic hypotension, disorientation, sedation), it is well recognized that those who fall present greater impairments in neuromechanical (NM) factors than do older non-fallers. Aging changes in balance and gait associated with NM impairments have also been consistently found to be among the most important risk factors for falls. What is presently unresolved, however, is which among the age-associated NM impairments, altered balance and mobility functions are best associated with falls and responsive to interventions (training).