Journal article
WITHIN-TRAIN NEUROMUSCULAR PROPAGATION VARIES WITH TORQUE IN PARALYZED HUMAN MUSCLE
Muscle & nerve, Vol.26(5), pp.673-680
11/2002
DOI: 10.1002/mus.10245
PMCID: PMC4693291
PMID: 12402290
Abstract
Electromyographic (EMG) recordings may serve an important role in predicting torque during repetitive activation of paralyzed muscle. We compared the initial M-wave to the subsequent M-waves of the same train under fatigued and recovered conditions in the paralyzed human soleus muscle. Sixteen individuals with chronic (
n
= 13) or acute paralysis (
n
= 3) had the tibial nerve activated before and after a repetitive supramaximal stimulation protocol. The mean within-train M-wave amplitude and median frequency increased ~20%, whereas the duration decreased ~15% compared with the initial M-wave of each train. During fatigue, there was a linear decrease in the difference between the initial M-wave amplitude and subsequent train (~20% to 8%). Following fatigue, this difference recovered to ~12%. The difference between the M-wave train average and the initial M-wave for amplitude, duration, and median frequency closely followed torque (Pearson correlations = 0.99, 0.94, and 0.98, respectively) during fatigue. We conclude that the difference between the later-occurring M-waves (average of the train) and initial M-wave is large when muscle torque is high and less when torque is low and, therefore, predicts torque during activation of paralyzed muscle. This difference in the within-train M-wave amplitude, duration, and median frequency may reflect a mechanical change, such as muscle shortening and increased muscle cross-sectional area during isometric contractions. Electromyographic feedback may assist in the optimization of neuromuscular electrical stimulation of paralyzed muscle.
Details
- Title: Subtitle
- WITHIN-TRAIN NEUROMUSCULAR PROPAGATION VARIES WITH TORQUE IN PARALYZED HUMAN MUSCLE
- Creators
- Ya-Ju Chang - Department of Physical Therapy, Chang Gung University, Taiwan, ROCRichard K Shields - Graduate Program in Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, 2600 Steiner Building, University of Iowa, Iowa City, Iowa 52242, USA
- Resource Type
- Journal article
- Publication Details
- Muscle & nerve, Vol.26(5), pp.673-680
- DOI
- 10.1002/mus.10245
- PMID
- 12402290
- PMCID
- PMC4693291
- NLM abbreviation
- Muscle Nerve
- ISSN
- 0148-639X
- eISSN
- 1097-4598
- Publisher
- Wiley
- Language
- English
- Date published
- 11/2002
- Academic Unit
- Orthopedics and Rehabilitation; Physical Therapy and Rehabilitation Science
- Record Identifier
- 9984047876302771
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