Interlimb Coordination During Locomotion: What Can be Adapted and Stored?

• Published in: Journal of neurophysiology Vol. 94; no. 4; pp. 2403 - 2415
• Main Authors: Reisman, Darcy S, Block, Hannah J, Bastian, Amy J
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01.10.2005
• Subjects: Adaptation, Physiological; Adult; Biomechanical Phenomena; Exercise Test - methods; Extremities - physiology; Humans; Locomotion - physiology; Psychomotor Performance - physiology; Walking - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.00089.2005

1 Department of Physical Therapy, University of Delaware, Newark, Delaware; 2 Kennedy Krieger Institute, Baltimore, Maryland; and 3 Department of Neuroscience, 4 Department of Neurology, and 5 Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland Submitted 24 January 2005; accepted in final form 8 June 2005 Interlimb coordination is critically important during bipedal locomotion and often must be adapted to account for varying environmental circumstances. Here we studied adaptation of human interlimb coordination using a split-belt treadmill, where the legs can be made to move at different speeds. Human adults, infants, and spinal cats can alter walking patterns on a split-belt treadmill by prolonging stance and shortening swing on the slower limb and vice versa on the faster limb. It is not known whether other locomotor parameters change or if there is a capacity for storage of a new motor pattern after training. We asked whether adults adapt both intra- and interlimb gait parameters during split-belt walking and show aftereffects from training. Healthy subjects were tested walking with belts tied (baseline), then belts split (adaptation), and again tied (postadaptation). Walking parameters that directly relate to the interlimb relationship changed slowly during adaptation and showed robust aftereffects during postadaptation. These changes paralleled subjective impressions of limping versus no limping. In contrast, parameters calculated from an individual leg changed rapidly to accommodate split-belts and showed no aftereffects. These results suggest some independence of neural control of intra- versus interlimb parameters during walking. They also show that the adult nervous system can adapt and store new interlimb patterns after short bouts of training. The differences in intra- versus interlimb control may be related to the varying complexity of the parameters, task demands, and/or the level of neural control necessary for their adaptation. Address for reprint requests and other correspondence: A. J. Bastian, Rm. G-04, Kennedy Krieger Inst., 707 N. Broadway, Baltimore, MD 21205 (E-mail: bastian{at}kennedykrieger.org )