Yes / Background: When trans-tibial amputees cross obstacles leading with their prosthesis, foot clearance is achieved using compensatory swing-phase kinematics. Such compensation would suggest able-bodied individuals normally use swing-phase ankle dorsiflexion to attain adequate obstacle clearance, however, direct evidence of such contribution is equivocal. The present study determined the contribution of sagittal plane ankle motion in achieving lead-limb clearance during obstacle negotiation.
Methods: 12 male able-bodied individuals (ages 18-30) completed obstacle crossing trials while walking on a flat surface. Lead-limb (right) ankle motion was manipulated using a knee-ankle-foot orthosis. Trials were completed with the ankle restricted at a neutral angle or unrestricted (allowing ~ ±15 plantar/dorsiflexion).
Findings: Restricted ankle motion caused significant increase in trail-limb foot placement distance before the obstacle (p=0.005); significant decrease in vertical toe clearance (p<0.003), vertical heel clearance (p=0.045) and lead-limb foot placement distance after the obstacle (p=0.045); but no significant changes in knee angle at instant of crossing or in average walking speed.
Interpretation: The shifts in foot placements altered the part of swing that the lead-limb was in when the foot crossed the obstacle, which led to a decrease in clearance. These adaptations may have been due to being unable to dorsiflex the ankle to ‘lift’ the toes in mid-swing or to being unable to plantarflex the ankle during initial contact following crossing, which changed how the lead-limb was to be loaded. These findings suggest individuals using ankle bracing or those with ankle arthrodesis, will have reduced gait safety when negotiating obstacles.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/7491 |
| Date | 04 October 2015 |
| Creators | Evangelopoulou, Eftychia, Twiste, M., Buckley, John |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Accepted Manuscript |
| Rights | © 2016 Elsevier. Reproduced in accordance with the publisher's self-archiving policy. This manuscript version is made available under the CC-BY-NC-ND 4.0 license |
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