Visual stabilization of posture in the elderly: Fallers vs. Nonfallers

Background. Postural instability is one of the important contributors to falling in observers aged 65 years and older. In this study we examine the role of vision in the relation between postural stability and falling, as well as in the relation between postural stability and the fear of falling. Methods. Community-dwelling adults 65 years and older were administered a questionnaire about their history of falls and fear of falling (N =185). Postural sway was measured in the same subjects with eyes open and eyes closed. Visual function was assessed by measures of visual acuity and contrast sensitivity. Results. The 29 subjects who reported falling in the last year showed less of a visual contribution to posture stabilization than those who reported no falls. Controlling for age and gender, there is a 2.13-fold increase in the likelihood of reporting falling for a 0.1 decrement in the visual stabilization index when it is measured within the context of reliable somatosensory feedback. Those who reported a fear of falling and those who reported no fear showed similar visual stabilization. Contrast sensitivity was significantly associated with visual stabilization when it was measured within the context of reliable somatosensory feedback. Conclusions. The visual contribution to postural stabilization is significantly greater in nonfallers compared to fallers, and it is significantly associated with contrast sensitivity.