TY - JOUR
T1 - An improved method for muscle force assessment in neuromuscular disease
AU - Brass, T. J.
AU - Loushin, M. K.H.
AU - Day, J. W.
AU - Iaizzo, P. A.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1996
Y1 - 1996
N2 - We describe here the reliability and validity of methods to quantify involuntary muscle torque induced by non-invasive nerve stimulation. A rigid apparatus was used to hold the subject's limb in a predetermined position and confine movement to a specific direction (i.e. ankle dorsiflexion or thumb adduction). An incorporated strain gauge was used to measure isometric torque, and all data were recorded by a data acquisition program. The innervating nerves were stimulated by surface electrodes, using either single stimuli to generate a twitch, or short trains of stimuli to produce tetanic contraction of the individual muscle under study. The average peak tetanic torque generated by the dorsiflexor muscles in healthy control was 20.4 ± 3.8 Nm and varied by 3.7% with repeated testing. The mean torque generated by the adductor pollicis muscle in controls was 1.5 ± 0.4 Nm and varied by 4.6% with repeated testing. In patient populations significant changes in activated torque were readily quantified, and the effects of treatment can be easily assessed. Furthermore, several specific parameters of recorded isometric contractions were measured; e.g. time between stimulus and torque onset, peak rate of torque development, time to peak torque, half-relaxation time, and others (none of which are measurable when using voluntary contraction of muscle). Compared to current assessment methods, monitoring muscle torque generated by nerve stimulation improves objectivity, reliability, and quantitative capabilities. The presented method has significant potential both in diagnosing neuromuscular disorders and determining treatment efficacy.
AB - We describe here the reliability and validity of methods to quantify involuntary muscle torque induced by non-invasive nerve stimulation. A rigid apparatus was used to hold the subject's limb in a predetermined position and confine movement to a specific direction (i.e. ankle dorsiflexion or thumb adduction). An incorporated strain gauge was used to measure isometric torque, and all data were recorded by a data acquisition program. The innervating nerves were stimulated by surface electrodes, using either single stimuli to generate a twitch, or short trains of stimuli to produce tetanic contraction of the individual muscle under study. The average peak tetanic torque generated by the dorsiflexor muscles in healthy control was 20.4 ± 3.8 Nm and varied by 3.7% with repeated testing. The mean torque generated by the adductor pollicis muscle in controls was 1.5 ± 0.4 Nm and varied by 4.6% with repeated testing. In patient populations significant changes in activated torque were readily quantified, and the effects of treatment can be easily assessed. Furthermore, several specific parameters of recorded isometric contractions were measured; e.g. time between stimulus and torque onset, peak rate of torque development, time to peak torque, half-relaxation time, and others (none of which are measurable when using voluntary contraction of muscle). Compared to current assessment methods, monitoring muscle torque generated by nerve stimulation improves objectivity, reliability, and quantitative capabilities. The presented method has significant potential both in diagnosing neuromuscular disorders and determining treatment efficacy.
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U2 - 10.3109/03091909609008382
DO - 10.3109/03091909609008382
M3 - Article
C2 - 8836925
AN - SCOPUS:0030110894
SN - 0309-1902
VL - 20
SP - 67
EP - 74
JO - Journal of Medical Engineering and Technology
JF - Journal of Medical Engineering and Technology
IS - 2
ER -