title: Why is walker-assisted gait metabolically expensive?
abstract: Walker-assisted gait is reported to be ∼200% more metabolically expensive than normal bipedal walking. However, previous studies compared different walking speeds. Here, we compared the metabolic power consumption and basic stride temporal-spatial parameters for 10 young, healthy adults walking without assistance and using 2-wheeled (2W), 4-wheeled (4W) and 4-footed (4F) walker devices, all at the same speed, 0.30m/s. We also measured the metabolic power demand for walking without any assistive device using a step-to gait at 0.30m/s, walking normally at 1.25m/s, and for repeated lifting of the 4F walker mimicking the lifting pattern used during 4F walker-assisted gait. Similar to previous studies, we found that the cost per distance walked was 217% greater with a 4F walker at 0.30m/s compared to unassisted, bipedal walking at 1.25m/s. Compared at the same speed, 0.30m/s, using a 4F walker was still 82%, 74%, and 55% energetically more expensive than walking unassisted, with a 4W walker and a 2W walker respectively. The sum of the metabolic cost of step-to walking plus the cost of lifting itself was equivalent to the cost of walking with a 4F walker. Thus, we deduce that the high cost of 4F walker assisted gait is due to three factors: the slow walking speed, the step-to gait pattern and the repeated lifting of the walker.
authors.affiliation: Department of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA.
authors.forename: Jonathon R
authors.initials: JR
authors.lastname: Priebe
authors.forename: Rodger
authors.initials: R
authors.lastname: Kram
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D014853:Walkers; D016138:Walking / Q000502:physiology*