Toshiki Kobayashi1, Michael S Orendurff2, Madeline L Singer3, Fan Gao4, K Bo Foreman3. 1. Department of Prosthetics and Orthotics, Faculty of Health Sciences, Hokkaido University of Science, Sapporo, Hokkaido, Japan; Orthocare Innovations, Mountlake Terrace, WA, USA. Electronic address: kobayashi-t@hus.ac.jp. 2. Orthocare Innovations, Mountlake Terrace, WA, USA; Lucille Packard Children's Hospital, Stanford University, Motion & Sports Performance Laboratory, CA, USA. 3. Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA. 4. Department of Health Care Sciences, School of Health Professions, University of Texas Southwestern Medical Center, TX, USA.
Abstract
BACKGROUND: Ankle-foot orthosis moment resisting plantarflexion has systematic effects on ankle and knee joint motion in individuals post-stroke. However, it is not known how much ankle-foot orthosis moment is generated to regulate their motion. The aim of this study was to quantify the contribution of an articulated ankle-foot orthosis moment to regulate ankle and knee joint motion during gait in individuals post-stroke. METHODS: Gait data were collected from 10 individuals post-stroke using a Bertec split-belt instrumented treadmill and a Vicon 3-dimensional motion analysis system. Each participant wore an articulated ankle-foot orthosis whose moment resisting plantarflexion was adjustable at four levels. Ankle-foot orthosis moment while walking was calculated under the four levels based on angle-moment relationship of the ankle-foot orthosis around the ankle joint measured by bench testing. The ankle-foot orthosis moment and the joint angular position (ankle and knee) relationship in a gait cycle was plotted to quantify the ankle-foot orthosis moment needed to regulate the joint motion. FINDINGS: Ankle and knee joint motion were regulated according to the amount of ankle-foot orthosis moment during gait. The ankle-foot orthosis maintained the ankle angular position in dorsiflexion and knee angular position in flexion throughout a gait cycle when it generated moment from -0.029 (0.011) to -0.062 (0.019) Nm/kg (moment resisting plantarflexion was defined as negative). INTERPRETATIONS: Quantifying the contribution of ankle-foot orthosis moment needed to regulate lower limb joints within a specific range of motion could provide valuable criteria to design an ankle-foot orthosis for individuals post-stroke.
BACKGROUND:Ankle-foot orthosis moment resisting plantarflexion has systematic effects on ankle and knee joint motion in individuals post-stroke. However, it is not known how much ankle-foot orthosis moment is generated to regulate their motion. The aim of this study was to quantify the contribution of an articulated ankle-foot orthosis moment to regulate ankle and knee joint motion during gait in individuals post-stroke. METHODS: Gait data were collected from 10 individuals post-stroke using a Bertec split-belt instrumented treadmill and a Vicon 3-dimensional motion analysis system. Each participant wore an articulated ankle-foot orthosis whose moment resisting plantarflexion was adjustable at four levels. Ankle-foot orthosis moment while walking was calculated under the four levels based on angle-moment relationship of the ankle-foot orthosis around the ankle joint measured by bench testing. The ankle-foot orthosis moment and the joint angular position (ankle and knee) relationship in a gait cycle was plotted to quantify the ankle-foot orthosis moment needed to regulate the joint motion. FINDINGS: Ankle and knee joint motion were regulated according to the amount of ankle-foot orthosis moment during gait. The ankle-foot orthosis maintained the ankle angular position in dorsiflexion and knee angular position in flexion throughout a gait cycle when it generated moment from -0.029 (0.011) to -0.062 (0.019) Nm/kg (moment resisting plantarflexion was defined as negative). INTERPRETATIONS: Quantifying the contribution of ankle-foot orthosis moment needed to regulate lower limb joints within a specific range of motion could provide valuable criteria to design an ankle-foot orthosis for individuals post-stroke.
Authors: Toshiki Kobayashi; Madeline L Singer; Michael S Orendurff; Fan Gao; Wayne K Daly; K Bo Foreman Journal: Clin Biomech (Bristol, Avon) Date: 2015-06-26 Impact factor: 2.063
Authors: Yvette L Kerkum; Annemieke I Buizer; Josien C van den Noort; Jules G Becher; Jaap Harlaar; Merel-Anne Brehm Journal: PLoS One Date: 2015-11-23 Impact factor: 3.240
Authors: Toshiki Kobayashi; Michael S Orendurff; Grace Hunt; Fan Gao; Nicholas LeCursi; Lucas S Lincoln; K Bo Foreman Journal: J Biomech Date: 2018-11-22 Impact factor: 2.712