How accuracy of foot-placement is affected by the size of the base of support and crutch support in stroke survivors and healthy adults

van der Veen, SM; Hammerbeck, U; Hollands, K

Abstract

Background
The high prevalence of falls due to trips and slips following stroke may signify difficulty controlling balance and adjusting foot-placement in response to the environment. We know very little about how controlling foot-placement is affected by balance requirements and the effects of stroke. Therefore, in this study the research question is how foot-placement control is affected by balance support from crutches and reducing or enlarging the base of support. By understanding how foot-placement control and balance deficits following stroke interact, rehabilitation efforts can be more effectively targeted towards the cause of poor mobility.

Methods
Young (N=13, 30±6 years) and older (N=10, 64±8 years) healthy adults and stroke survivors (N=11, 67±9 years) walked to targets on an instrumented treadmill with or without crutch support for balance. Targets were randomized to either reduce or increase the base of support in the antero-posterior (AP) or medio-lateral (ML) direction. Mean and absolute foot-placement error were measured using motion analysis. These outcomes were compared using repeated measures ANCOVA with walking speed as a covariate.

Results
Overall, stroke survivors missed more targets (9.1±2.3%, p=0.001) than young (1.0±2.5%) and older (0.2±2.1%) healthy adults (p=0.001). However, there were no significant differences between groups in foot-placement error. Crutch support reduced both AP and ML foot-placement error (p=<0.001, AP 5.2±0.5cm unsupported, 4.1±0.4cm supported, ML 2.3±0.2cm unsupported, 1.9±0.2cm supported) for all participants. Interaction effects indicate crutch support reduced foot-placement error more when narrowing (unsupported 2.8±0.2cm, supported 1.8±0.2cm) than widening (unsupported 2.6±0.4cm, supported 2.4±0.4cm) steps (p<0.001),

Significance
Stroke survivors have greater difficulty accurately adjusting steps in response to the environment. Crutch support reduces foot-placement error for all steps, but particularly when narrowing foot-placement. These results provide support for the implication of walking aids, which support balance to improve ability to adjust footplacement in response to the environment.

• Journal Article Type: Article
• Acceptance Date: Dec 6, 2019
• Online Publication Date: Dec 19, 2019
• Publication Date: Feb 1, 2020
• Deposit Date: Jan 23, 2020
• Publicly Available Date: Dec 19, 2020
• Journal: Gait & Posture
• Print ISSN: 0966-6362
• Electronic ISSN: 1879-2219
• Publisher: Elsevier
• Volume: 76
• Pages: 224-230
• DOI: https://doi.org/10.1016/j.gaitpost.2019.12.007
• Publisher URL: https://doi.org/10.1016/j.gaitpost.2019.12.007
• Related Public URLs: https://www.sciencedirect.com/journal/gait-and-posture