Balance control in very old adults with and without visual impairment.

Good balance, an important ability in controlling body movement, declines with age. Also, balance appears to decrease when visual input is restricted, while this has been poorly investigated among visually impaired very old adults. The objective of this study is thus to explore whether the balance control of the very old differs with varying degrees of visual impairment. This cross-sectional study was conducted in community centers and residential care homes. Thirty-three visually impaired (17 = low vision; 16 = blind) and 15 sighted elderly aged ≥ 70 years participated in the study. All participants were assessed: (1) concentric isokinetic strength of the knee extensors and flexors; (2) a sensory organization test to measure their ability to use somatosensory, visual, and vestibular information to control standing balance; (3) a perturbed double-leg stance test to assess the ability of the automatic motor system to quickly recover following an unexpected external disturbance; (4) the five times sit-to-stand test. Compared with low-vision subjects, the sighted elderly achieved higher peak torque-to-body weight ratios in concentric knee extension. The sighted elderly showed less body sway than the low vision and blind subjects in sensory conditions where they benefited from visual inputs to help them maintain standing balance. The sighted and low-vision subjects achieved smaller average body sway angles during forward and backward platform translations compared to the blind subjects. Low vision and blindness decrease balance control in elderly.