Oxygen Consumption During Stair Ascent and Descent — A Comparison between Subjects with Normal and Impaired Vision

Visual information is important to maintaining balance. Under conditions of blurred vision, subjects are more cautious and increase lower limb kinaesthetic information during stair descent. Increased kinaesthetic adjustment may lead to an increase in oxygen consumption, the consequences of which could be significant in people with compromised cardiopulmonary reserve such as the frail, elderly and subjects with chronic respiratory disease. To first determine if visual impairment influences oxygen consumption during stair climbing, this study attempted to determine the difference in energy expenditure in terms of oxygen consumption in healthy subjects with normal and impaired vision, during stair ascent and descent. Ten subjects aged between 20 and 22 years were recruited and assigned in random sequence to climb up or down eight flights of stairs (FOS), with and without a pair of goggles designed to reduce visual acuity by about 50%. Oxygen consumption during stair ascent and descent was measured. Results showed that the oxygen consumed by subjects having descended eight FOS was significantly greater when visually impaired compared to normal vision (p = 0.036). Visual acuity has no influence on oxygen consumption during stair ascent. Further investigation of a larger sample of elderly patients with compromised cardiopulmonary function is recommended.