Gait of a deafferented subject without large myelinated sensory fibers below the neck.
We evaluated the gait pattern of a deafferented subject who suffered a permanent loss of large sensory myelinated fibers below the neck following an acute episode of purely sensory neuropathy 21 years ago. The subject has developed several strategies to achieve a secure gait, namely: (1) a reduction of the degrees of freedom by freezing the knee articulations during the stance phase, (2) a preservation of body balance by enlarging his base of support, and (3) visual monitoring of his step by stabilizing the head-trunk linkage together with a characteristic forward tilt. As a result, the gait of the deafferented subject lacks the fluidity of normal gait. Compared with normal subjects, the gait pattern of the deafferented subjects is characterized by a shorter cycle length, a longer cycle duration, a slower speed, and a lower cadence. Using a dual-task paradigm, the attentional demands for walking were particularly important (as indexed by longer probe reaction times) during the double-support phase, suggesting that the deafferented subject uses the double-support phase as a transitory stable phase to update cognitively the postural features necessary for generating his next step.
Lajoie
Y
Y
Laboratoire de Performance Motrice Humaine, Université Laval, Québec, Canada.
Teasdale
N
N
Cole
J D
JD
Burnett
M
M
Bard
C
C
Fleury
M
M
Forget
R
R
Paillard
J
J
Lamarre
Y
Y
D003714:Denervation; D004576:Electromyography; D005684:Gait / Q000502:physiology*; D006801:Humans; D009186:Myelin Sheath / Q000502:physiology; D009333:Neck / Q000294:innervation*; D009412:Nerve Fibers / Q000502:physiology*