Changing coupling between the arms and legs with slow walking speeds alters regulation of somatosensory feedback
- PDF / 2,015,082 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 78 Downloads / 142 Views
RESEARCH ARTICLE
Changing coupling between the arms and legs with slow walking speeds alters regulation of somatosensory feedback Taryn Klarner1,2,3 · Gregory E. P. Pearcey2,3,4 · Yao Sun2,3,4 · Trevor S. Barss2,3,4 · E. Paul Zehr2,3,4,5 Received: 1 January 2020 / Accepted: 13 April 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Arm swing movement is coordinated with movement of the legs during walking, where the frequency of coordination depends on walking speed. At typical speeds, arm and leg movements, respectively, are frequency locked in a 1:1 ratio but at slow speeds this changes to a 2:1 ratio. It is unknown if the changes in interlimb ratio that accompany slow walking speeds alters regulation of somatosensory feedback. To probe the neural interactions between the arms and legs, somatosensory linkages in the form of interlimb cutaneous reflexes were examined. It was hypothesized that different interlimb frequencies and walking speeds would result in changes in the modulation of cutaneous reflexes between the arms and legs. To test this hypothesis, participants walked in four combinations of walking speed (typical, slow) and interlimb coordination (1:1, and 2:1), while cutaneous reflexes and background muscle activity were evaluated with stimulation applied to the superficial peroneal nerve at the ankle and superficial radial nerve at the wrist. Results show main effects of interlimb coordination and walking speed on cutaneous reflex modulation, effects are largest in the swing phase, and a directional coupling was observed, where changes in the frequency of arm movements had a greater effect on muscle activity in the legs compared to the reverse. Task-dependent modulation was also revealed from stimulation at local and remote sources. Understanding the underlying neural mechanisms for the organization of rhythmic arm movement, and its coordination with the legs in healthy participants, can give insight into pathological walking, and will facilitate the development of effective strategies for the rehabilitation of walking. Keywords Walking speed · Interlimb coordination · Electromyography · Cutaneous reflexes
Introduction
Communicated by Winston D Byblow. * E. Paul Zehr [email protected] http://www.zehr.ca 1
School of Kinesiology, Lakehead University, Thunder Bay, Canada
2
Rehabilitation Neuroscience Laboratory, University of Victoria, PO Box 3010 STN CSC, Victoria, BC V8W 3P1, Canada
3
Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
4
Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
5
Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
Understanding the dynamic interactions between arm and leg coordination is important and timely, since arm movement can facilitate locomotor rehabilitation (Ferris et al. 2006; Dietz and Michel 2009; Zehr et al. 2009, 2016; Klimstra et al. 2009; de Kam et al. 2013; Guertin 2013; Klarner et al. 2016; Zhou et al. 2018a, b; K
Data Loading...
