Rapid Assessment of Age-Related Differences in Standing Balance

As life expectancy continues to rise, in the future there will be an increasing number of older people prone to falling. Accordingly, there is an urgent need for comprehensive testing of older individuals to collect data and to identify possible risk factors for falling. Here we use a low-cost force platform to rapidly assess deficits in balance under various conditions. We tested 21 healthy older adults and 24 young adults during static stance, unidirectional and rotational displacement of their centre of pressure (COP). We found an age-related increase in postural sway during quiet standing and a reduction of maximal COP displacement in unidirectional and rotational displacement tests. Our data show that even low-cost computerized assessment tools allow for the comprehensive testing of balance performance in older subjects. 1. Introduction 1.1. Balance and Aging Several mechanisms have been proposed to explain the changes in balance during aging. Since aging affects almost all physiological processes [1], reduction in postural stability can be explained by various factors, such as a loss of receptor cells in the vestibular organ [2], impaired sensory perception, a decline in muscle strength, and increased reaction times [3]. Especially proprioception, which refers to the sensing where the body is located in space [4], is known to be a critical source of sensory feedback for the preservation of balance during upright standing in the elderly (for review see [5]). Besides physiological alterations, impaired balance at high age can also be explained by a general age-related reduction in physical activities, which in turn may further reduce the ability of living a physically active life [6]. Balance disorders represent a growing public health concern due to the association with falls and fall-related injuries. Thereby falls often mark the beginning of a loss of independence and are the leading cause of injury-related institutionalizations in older adults [3, 7]. Consequently, the documentation and understanding of age-related changes in balance performance is of utmost importance [7]. 1.2. Methods for Assessing Standing Balance Clinical scales, in addition to tests of stance and reach, are often used to rate balance performance. Functional assessments of this type have the advantage that they can be quickly applied and rarely require expensive equipment [8] but they often lack a more detailed rating of impairment [9]. By contrast, posturography is used to measure and quantify postural sway [9, 10] by assessing COP deflections [11]. Force platforms are the