Katherine L Hsieh1, Riley C Sheehan2, Jason M Wilken3, Jonathan B Dingwell4. 1. Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA; Military Performance Lab, Center for the Intrepid, JBSA Ft. Sam Houston, TX, USA. 2. Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA; Military Performance Lab, Center for the Intrepid, JBSA Ft. Sam Houston, TX, USA; Department of Kinesiology & Health Education, The University of Texas at Austin, Austin, TX, USA. 3. Military Performance Lab, Center for the Intrepid, JBSA Ft. Sam Houston, TX, USA; DoD-VA Extremity Trauma and Amputation Center of Excellence (EACE), USA. 4. Department of Kinesiology & Health Education, The University of Texas at Austin, Austin, TX, USA. Electronic address: dingwell@psu.edu.
Abstract
INTRODUCTION: Maintaining stability, especially in the mediolateral direction, is important for successful walking. Navigating in the community, however, may require people to reduce stability to make quick lateral transitions, creating a tradeoff between stability and maneuverability. Walking slower can improve stability during steady state walking, but there remains a need to better understand how walking speed influences maneuverability. This study investigated how walking at different speeds influenced how individuals modulate both stability and maneuverability in a virtual obstacle course. METHODS: Fifteen healthy adults walked on a treadmill in a virtual environment for 6 trials each at typical and slower speed. Participants made repeated transitions between virtual sets of arches displayed in any of 4 lanes. Participants were instructed to walk under the arches and hit as few arches as possible. To quantify stability, mean step width and mean lateral margin of stability (Mean MOS) were calculated and averaged for ipsilateral and contralateral steps. To quantify maneuverability, the number of arches hit when entering or exiting each arch set was calculated and averaged for each condition. RESULTS: Participants exhibited high levels of variability in their stepping patterns. Mean MOS and mean step width were significantly greater for the typical speed than slower speed for the ipsilateral steps (p < 0.001). Participants hit more arches during the typical speed than during the slow speed (p = 0.039). CONCLUSION: When walking at the slower speed, healthy individuals exhibited decreased stability of ipsilateral steps, but increased maneuverability and better transition performance.
INTRODUCTION: Maintaining stability, especially in the mediolateral direction, is important for successful walking. Navigating in the community, however, may require people to reduce stability to make quick lateral transitions, creating a tradeoff between stability and maneuverability. Walking slower can improve stability during steady state walking, but there remains a need to better understand how walking speed influences maneuverability. This study investigated how walking at different speeds influenced how individuals modulate both stability and maneuverability in a virtual obstacle course. METHODS: Fifteen healthy adults walked on a treadmill in a virtual environment for 6 trials each at typical and slower speed. Participants made repeated transitions between virtual sets of arches displayed in any of 4 lanes. Participants were instructed to walk under the arches and hit as few arches as possible. To quantify stability, mean step width and mean lateral margin of stability (Mean MOS) were calculated and averaged for ipsilateral and contralateral steps. To quantify maneuverability, the number of arches hit when entering or exiting each arch set was calculated and averaged for each condition. RESULTS:Participants exhibited high levels of variability in their stepping patterns. Mean MOS and mean step width were significantly greater for the typical speed than slower speed for the ipsilateral steps (p < 0.001). Participants hit more arches during the typical speed than during the slow speed (p = 0.039). CONCLUSION: When walking at the slower speed, healthy individuals exhibited decreased stability of ipsilateral steps, but increased maneuverability and better transition performance.
Authors: Krissy M T Goutier; Sophie L Jansen; Corinne G C Horlings; Ursula M Küng; John H J Allum Journal: Age Ageing Date: 2010-06-17 Impact factor: 10.668