Intervention to Enhance Lateral Balance Function and Prevent Falls in Aging

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).

Eligibility Criteria:
Inclusion Criteria:

* 65 years of age or older
* Body Mass Index in range of 18.5 to 30

Exclusion Criteria:

* Timed -Up-and-Go faster than 12 seconds (very low fall risk)
* Persons advised by their doctor not to exercise
* Evidence of any medical condition as determined by physician or results of blood test that would lead to increased risk of accident, injury or illness due to any aspect of proposed tests and interventions, including resistance training
* Persons with history of brain, nerve or muscle disorder including Parkinson's disease, stroke, peripheral neuropathy or myopathy
* Persons with reported hip or knee joint replacement in past 6 months
* Persons with significant foot deformities or amputation as determined by a qualified medical professional
* Persons with sedative medications including hypnotics, anxiolytic, opioids, neuroleptics, or sedating antidepressants
* Persons using medications that pose a significant bleeding risks as determined by a qualified medical professional
* Any significant functional limitation as determined by a score of zero on any of the six daily tasks of the Instrumental Activities of Daily Living Scale (IADL) that enable independent living in the community. The six functional items used are: A. Telephone, B. Shopping, C. Food Preparation, D. Housekeeping, E. Laundry, and F. Transportation
* Non-ambulatory (unable to walk)
* Persons using a gait device at all times in home environment
* Cognitive impairment defined as Mini-Mental State Exam score \<24
* Persons with uncorrected vision limiting visual function or eye surgery in ast 6 months
* Persons with uncorrected hearing impairment limiting daily activities or communication as determined by a qualified medical professional
* Persons with major depression (Centers for Epidemiological Studies Depression Survey score \>16)