Dynamic margins of stability during human walking in destabilizing environments

JOURNAL OF BIOMECHANICS

卷:45

Article

Young, Patricia M. McAndrew²  Wilken, Jason M.³  Dingwell, Jonathan B.¹ 

[1] Univ Texas Austin, Dept Kinesiol & Hlth Educ, Austin, TX 78712 USA

[2] Univ Texas Austin, Dept Biomed Engn, Austin, TX 78712 USA

[3] Brooke Army Med Ctr, Dept Orthoped & Rehabil, Ctr Intrepid, Ft Sam Houston, TX 78234 USA

关键词: Walking;    Dynamic stability margins;    Perturbations;    Pseudo-random;    Visual;    Walking surface;   

DOI  :  10.1016/j.jbiomech.2011.12.027

来源: Elsevier

【 摘 要 】

Understanding how humans maintain stability when walking, particularly when exposed to perturbations, is key to preventing falls. Here, we quantified how imposing continuous, pseudorandom anterior-posterior (AP) and mediolateral (ML) oscillations affected the control of dynamic walking stability. Twelve subjects completed five 3-minute walking trials in the Computer Assisted Rehabilitation ENvironment (CAREN) system under each of 5 conditions: no perturbation (NOP), AP platform (APP) or visual (APV) or ML platform (MLP) or visual (MLV) oscillations. We computed AP and ML margins of stability (MOS) for each trial. Mean MOSml were consistently slightly larger during all perturbation conditions than during NOP (p <= 0.038). Mean MOSap for the APP, MLP and MLV oscillations were significantly smaller than during NOP (p < 0.0005). Variability of both MOSap and MOSml was significantly greater during the MLP and MLV oscillations than during NOP (p < 0.0005). We also directly quantified how the MOS on any given step affected the MOS on the following step using first-return plots. There were significant changes in step-to-step MOSml dynamics between experimental conditions (p < 0.0005). These changes suggested that subjects may have been trying to control foot placement, and consequently stability, during the perturbation conditions. Quantifying step-to-step changes in margins of dynamic stability may be more useful than mean MOS in assessing how individuals control walking stability. (c) 2012 Elsevier Ltd. All rights reserved.

【 授权许可】

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