Establishing baseline centre of pressure measures in older adults with and without simulated vision impairment using the Nintendo Wii Balance Board

Abstract

Purpose : As a practical alternative to force plates, clinical researchers have begun to use the Nintendo Wii Balance Board (WBB) to assess balance. The WBB has been shown to be valid & reliable and is portable. It can identify subtle changes in posture that cannot be identified by visual inspection alone, making it ideal for measuring postural stability and fall risk in low vision. This study aims to establish baseline centre of pressure characteristics before the onset of visual impairment in older adults, by measuring postural control in older adults with and without simulated vision impairment.

Methods : Community-dwelling older adults, aged 50 and older, were recruited at community events geared to their age group. Visual acuity was measured using the Freiburg Visual Acuity Test. Anyone with a vision impairment (visual acuity >20/40) was excluded. Participants reported their fall history and were evaluated for fear of falling using the Activities-Specific Balance Confidence (ABC) Scale. The Timed Up-and-Go (TUG) was used to measure global balance and the WBB measured postural control under eyes closed, normal correction and simulated visual impairment (20/80 or 20/200) conditions.

Results : A total of 42 older adults (7 Male, 35 Female) ranged in age from 51-90 years (M: 68.5, SD: 9.89) participated in this study. TUG times significantly differed between normal correction and both vision impairment conditions (20/80: t(17) = -4.37, p <0.001, d=-2.12; 20/200: t(24) = -3.07, p = 0.005, d=-1.25). WBB normal correction and vision impairment conditions differed in total displacement (t(15) = -3.48, p=0.03, d=-1.8) and anterior-posterior (A-P) amplitude (t(15) = -2.99, p=0.009, d=-1.54), but only in the 20/80 condition.

Conclusions : Preliminary results show significant differences in global balance (TUG) between normal correction and simulated vision impairment. Significant differences in A-P amplitude between normal correction and the 20/80 impairment indicate an increased risk of falls. Not seeing the same in the 20/200 condition indicates the simulated impairment is enough to increase anxiety, causing participants to adopt a stiffening strategy which results in lower average A-P amplitude compared to the normal correction condition. Future work will compare these results to those of younger adults and older adults with actual vision impairment.

This is a 2020 ARVO Annual Meeting abstract.