Distinct patterns of motor unit behavior during muscle spasms in spinal cord injured subjects

Journal of Neurophysiology
C K Thomas, B H Ross

Abstract

Surface electromyograms (EMG) and force were recorded during repeated involuntary spasms of paralyzed triceps surae muscles of four men with chronic cervical spinal cord injury. The firing rates of 78 medial gastrocnemius (MG) motor units also were recorded intramuscularly with tungsten microelectrodes. Spasms typically involved a relatively rapid rise, then a more gradual fall in triceps surae EMG and torque. Motor unit firing rates either increased and then decreased with the spasm intensity (54%) or were relatively constant (26%), firing mainly at 2-10 Hz. The remaining units (20%) produced trains that included one or several doublets. Mean peak spasm firing rates were 18 +/- 9 Hz (mean +/- SD) for rate modulated units and 11 +/- 10 Hz for units with little or no rate modulation. Some motor units fired at rates comparable with those recorded previously during maximum voluntary contractions performed by intact subjects. Others fired at rates below the minimum usually seen when normal units are first recruited (< 6 Hz). Doublets (interspike interval < 10 ms) often repeated every 123-333 ms, or were interspersed in trains firing at low steady rates (< 11 Hz). This study shows that rate coding for many motor units appears to be ...Continue Reading

References

Nov 1, 1977·Journal of Neurophysiology·A W Monster, H Chan
Oct 1, 1992·Muscle & Nerve·C L RiceB Bigland-Ritchie
Nov 1, 1986·The Journal of Physiology·K E HagbarthE U Wallin
Jul 1, 1969·Acta Physiologica Scandinavica·K E Hagbarth, A B Vallbo
Dec 1, 1983·Journal of Neurophysiology·F BellemareB Bigland-Ritchie
Jun 1, 1983·The Journal of Physiology·P Bawa, B Calancie
Oct 1, 1995·Muscle & Nerve·J J GemperlineW Z Rymer

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Citations

Dec 22, 1999·Journal of Neurophysiology·C K ThomasB Bigland-Ritchie
Oct 23, 2002·Journal of Applied Physiology·Jane E Butler, Christine K Thomas
Aug 16, 2005·Journal of Applied Physiology·Douglas M WallaceChristine K Thomas
Aug 2, 2013·Acta Physiologica·C K ThomasI Zijdewind
Apr 15, 2005·Journal of Neurophysiology·Mary Kay FloeterJeffrey Statland
Jan 20, 2006·Muscle & Nerve·Jane E ButlerChristine K Thomas
Sep 15, 2006·Movement Disorders : Official Journal of the Movement Disorder Society·Gea DrostMachiel J Zwarts
Oct 16, 2001·Journal of Neurophysiology·D J BennettM Siu
Jul 19, 2005·Muscle & Nerve·Christine K Thomas, Inge Zijdewind
Sep 3, 2009·Neurorehabilitation and Neural Repair·Sherif M ElbasiounyVivian K Mushahwar
Dec 3, 2014·Frontiers in Human Neuroscience·Inge ZijdewindChristine K Thomas
Jan 15, 2015·The Journal of Spinal Cord Medicine·Maryam ZoghiDavid Morgan
Oct 16, 2001·Journal of Neurophysiology·D J BennettM Gorassini
Feb 9, 2012·The Journal of Physiology·Inge Zijdewind, Christine K Thomas
Nov 12, 2009·Brain : a Journal of Neurology·Christine K ThomasCliff S Klein
Nov 18, 2016·Journal of Neurophysiology·Christine K ThomasCliff S Klein
Feb 1, 2008·Journal of Neurophysiology·D J Bennett
Jul 16, 2014·Journal of Electromyography and Kinesiology : Official Journal of the International Society of Electrophysiological Kinesiology·C K ThomasR W Morris

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