Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractions

Aim:  To compare the discharge patterns of motor unit populations from different locations within the upper trapezius muscle during brief submaximal constant‐force contractions.

[1]  K Roeleveld,et al.  EMG amplitude distribution changes over the upper trapezius muscle are similar in sustained and ramp contractions , 2006, Acta physiologica.

[2]  E. Henneman Relation between size of neurons and their susceptibility to discharge. , 1957, Science.

[3]  B. Maton,et al.  The fatigability of two agonistic muscles in human isometric voluntary submaximal contraction: an EMG study , 2004, European Journal of Applied Physiology and Occupational Physiology.

[4]  S. Gandevia Spinal and supraspinal factors in human muscle fatigue. , 2001, Physiological reviews.

[5]  R H Westgaard,et al.  Functional subdivision of the upper trapezius muscle during maximal isometric contractions. , 1995, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[6]  B. Maton,et al.  The fatigability of two agonistic muscles in human isometric voluntary submaximal contraction: an EMG study , 2004, European Journal of Applied Physiology and Occupational Physiology.

[7]  Dario Farina,et al.  The change in spatial distribution of upper trapezius muscle activity is correlated to contraction duration. , 2008, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[8]  C. D. De Luca,et al.  Motor unit control properties in constant-force isometric contractions. , 1996, Journal of neurophysiology.

[9]  A. Monster,et al.  Isometric force production by motor units of extensor digitorum communis muscle in man. , 1977, Journal of neurophysiology.

[10]  Dario Farina,et al.  Periodic increases in force during sustained contraction reduce fatigue and facilitate spatial redistribution of trapezius muscle activity , 2007, Experimental Brain Research.

[11]  C. D. De Luca,et al.  Behaviour of human motor units in different muscles during linearly varying contractions , 1982, The Journal of physiology.

[12]  S E Mathiassen,et al.  Physiological comparison of three interventions in light assembly work: reduced work pace, increased break allowance and shortened working days , 1996, International archives of occupational and environmental health.

[13]  A Eriksson,et al.  Fiber type composition of the human male trapezius muscle: enzyme-histochemical characteristics. , 1990, The American journal of anatomy.

[14]  Dario Farina,et al.  Standardising surface electromyogram recordings for assessment of activity and fatigue in the human upper trapezius muscle , 2002, European Journal of Applied Physiology.

[15]  G. A. Robinson,et al.  Behavior of motor units in human biceps brachii during a submaximal fatiguing contraction. , 1994, Journal of applied physiology.

[16]  R. Johansson,et al.  Reflex origin for the slowing of motoneurone firing rates in fatigue of human voluntary contractions. , 1986, The Journal of physiology.

[17]  Roger M. Enoka,et al.  Physiology of the motor neuron and the motor unit , 2004 .

[18]  Chris Jensen,et al.  Functional subdivision of the upper trapezius muscle during low-level activation , 1997, European Journal of Applied Physiology and Occupational Physiology.

[19]  R. Gorman,et al.  Decline in spindle support to alpha‐motoneurones during sustained voluntary contractions. , 1991, The Journal of physiology.

[20]  Dario Farina,et al.  Experimental muscle pain changes the spatial distribution of upper trapezius muscle activity during sustained contraction , 2006, Clinical Neurophysiology.

[21]  Svend Erik Mathiassen,et al.  Electromyographic activity in the shoulder-neck region according to arm position and glenohumeral torque , 2004, European Journal of Applied Physiology and Occupational Physiology.

[22]  K. McGill,et al.  Triphasic behavioral response of motor units to submaximal fatiguing exercise , 1990, Muscle & nerve.

[23]  C D Marsden,et al.  "Muscular wisdom" that minimizes fatigue during prolonged effort in man: peak rates of motoneuron discharge and slowing of discharge during fatigue. , 1983, Advances in neurology.

[24]  Kevin C. McGill,et al.  EMGLAB: An interactive EMG decomposition program , 2005, Journal of Neuroscience Methods.