Experimental muscle pain changes the spatial distribution of upper trapezius muscle activity during sustained contraction

Arendt-Nielsen, 1997, Induction and assessment of experimental pain in human skin, muscle and viscera, 93 Arendt-Nielsen, 1996, The influence of low back pain on muscle activity and coordination during gait: a clinical and experimental study, Pain., 64, 231, 10.1016/0304-3959(95)00115-8 Bigland-Ritchie, 1986, Reflex origin for the slowing of motoneurone firing rates in fatigue of human voluntary contractions, J Physiol, 379, 451, 10.1113/jphysiol.1986.sp016263 Birch, 2000, The influence of experimental muscle pain on motor unit activity during low-level contraction, Eur J Appl Physiol, 83, 200, 10.1007/s004210000279 De Luca, 1984, Myoelectrical manifestations of localized muscle fatigue in humans, Crit Rev Biomed Eng, 11, 251 DeLuca, 1988, Surface myoelectric signal cross-talk among muscles of the leg, Electroencephalogr Clin Neurophysiol, 69, 568, 10.1016/0013-4694(88)90169-1 Dimitrova, 2002, Neither high-pass filtering nor mathematical differentiation of the EMG signals can considerably reduce cross-talk, J Electromyogr Kinesiol, 12, 235, 10.1016/S1050-6411(02)00008-1 Enoka, 1995, Morphological features and activation patterns of motor units, J Clin Neurophysiol, 12, 538, 10.1097/00004691-199511000-00002 Fallentin, 1993, Motor unit recruitment during prolonged isometric contractions, Eur J Appl Physiol, 67, 335, 10.1007/BF00357632 Farina, 2002, Motor unit recruitment strategies investigated by surface EMG variables, J Appl Physiol, 92, 235, 10.1152/jappl.2002.92.1.235 Farina, 2002, Standardising surface electromyogram recordings for assessment of activity and fatigue in the human upper trapezius muscle, Eur J Appl Physiol, 86, 469, 10.1007/s00421-001-0574-0 Farina, 2004, Effect of experimental muscle pain on motor unit firing rate and conduction velocity, J Neurophysiol, 91, 1250, 10.1152/jn.00620.2003 Farina, 2005, Experimental muscle pain decreases voluntary EMG activity but does not affect the muscle potential evoked by transcutaneous electrical stimulation, Clin Neurophysiol, 116, 1558, 10.1016/j.clinph.2005.03.009 Farina, 2005, Experimental muscle pain reduces initial motor unit discharge rates during sustained submaximal contractions, J Appl Physiol, 98, 999, 10.1152/japplphysiol.01059.2004 Gandevia, 2001, Spinal and supraspinal factors in human muscle fatigue, Physiol Rev, 81, 1725, 10.1152/physrev.2001.81.4.1725 Ge, 2005, Gender-specific differences in electromyographic changes and perceived pain induced by experimental muscle pain during sustained contractions of the upper trapezius muscle, Muscle Nerve, 32, 726, 10.1002/mus.20410 Graven-Nielsen, 1997, Effects of experimental muscle pain on muscle activity and coordination during static and dynamic motor function, Electroencephalogr Clin Neurophysiol, 105, 156, 10.1016/S0924-980X(96)96554-6 Graven-Nielsen, 1997, In vivo model of muscle pain: quantification of intramuscular chemical, electrical, and pressure changes associated with saline-induced muscle pain in humans, Pain, 69, 137, 10.1016/S0304-3959(96)03270-8 Hagg, 1992, Interpretation of EMG spectral alterations and alteration indexes at sustained contraction, J Appl Physiol, 73, 1211, 10.1152/jappl.1992.73.4.1211 Hayward, 1988, Increased inhibitory effects on close synergists during muscle fatigue in the decerebrate cat, Brain Res, 440, 199, 10.1016/0006-8993(88)91178-X Holtermann, 2005, Inhomogeneities in muscle activation reveal motor unit recruitment, J Electromyogr Kinesiol, 15, 131, 10.1016/j.jelekin.2004.09.003 Jamison, 1993, Muscle synergies and isometric torque production – influence of supination and pronation level on elbow flexion, J Neurophysiol, 70, 947, 10.1152/jn.1993.70.3.947 Jensen, 1997, Functional subdivision of the upper trapezius muscle during low-level activation, Eur J Appl Physiol, 76, 335, 10.1007/s004210050257 Kleine, 2000, Surface EMG mapping of the human trapezius muscle: the topography of monopolar and bipolar surface EMG amplitude and spectrum parameters at varied forces and in fatigue, Clin Neurophysiol, 111, 686, 10.1016/S1388-2457(99)00306-5 Kleine, 2001, Influence of motoneuron firing synchronization on SEMG characteristics in dependence of electrode position, J Appl Physiol, 91, 1588, 10.1152/jappl.2001.91.4.1588 Lapatki, 2004, A thin, flexible multielectrode grid for high-density surface EMG, J Appl Physiol, 96, 327, 10.1152/japplphysiol.00521.2003 Lapatki, 2006, Topographical characteristics of motor units of the lower facial musculature revealed by means of high-density surface EMG, J Neurophysiol, 95, 342, 10.1152/jn.00265.2005 Lund, 1991, The pain-adaptation model: a discussion of the relationship between chronic musculoskeletal pain and motor activity, Can J Physiol Pharmacol, 69, 683, 10.1139/y91-102 Madeleine, 2005, Experimental muscle pain increases mechanomyographic signal activity during sub-maximal isometric contractions, J Electromyogr Kinesiol, 15, 27, 10.1016/j.jelekin.2004.06.006 Madeleine, 1999, Shoulder muscle coordination during chronic and acute experimental neck–shoulder pain. An occupational study, Eur J Appl Physiol, 79, 127, 10.1007/s004210050486 Madeleine, 1999, Reorganisation of human step initiation during acute experimental muscle pain, Gait Posture, 10, 240, 10.1016/S0966-6362(99)00036-3 Masuda, 1987, Skeletal-muscles from which the propagation of motor unit action-potentials is detectable with a surface electrode array, Electroencephalogr Clin Neurophysiol, 67, 421, 10.1016/0013-4694(87)90005-8 Mathiassen, 1995, Normalisation of surface EMG ampltude from the upper trapezius muscle in ergonomic studies – a review, J Electromyogr Kinesiol, 5, 197, 10.1016/1050-6411(94)00014-X Mense, 1985, Different types of slowly conducting afferent units in cat skeletal muscle and tendon, J Physiol, 363, 403, 10.1113/jphysiol.1985.sp015718 Merletti, 1990, Myoelectric manifestations of fatigue in voluntary and electrically elicited contractions, J Appl Physiol, 69, 1810, 10.1152/jappl.1990.69.5.1810 Palmerud, 1998, Consequences of trapezius relaxation on the distribution of shoulder muscle forces: an electromyographic study, J Electromyogr Kinesiol, 8, 185, 10.1016/S1050-6411(97)00033-3 Prutchi, 1995, A high-resolution large array (Hrla) surface emg system, Med Eng Phys, 17, 442, 10.1016/1350-4533(94)00016-3 Sohn, 2000, Inhibition of motor unit firing during experimental muscle pain in humans, Muscle Nerve, 23, 1219, 10.1002/1097-4598(200008)23:8<1219::AID-MUS10>3.0.CO;2-A Sohn, 2004, Effects of experimental muscle pain on mechanical properties of single motor unit in human masseter, Clin Neurophysiol, 115, 76, 10.1016/S1388-2457(03)00318-3 Staudenmann, 2005, Towards optimal multi-channel EMG electrode configurations in muscle force estimation: a high density EMG study, J Electromyogr Kinesiol, 15, 1, 10.1016/j.jelekin.2004.06.008 Stohler, 1994, Effects of noxious stimulation of the jaw muscles on the sensory experience of volunteer human subjects, 55 Svensson, 1998, Experimental muscle pain does not cause long-lasting increases in resting electromyographic activity, Muscle Nerve, 21, 1382, 10.1002/(SICI)1097-4598(199811)21:11<1382::AID-MUS4>3.0.CO;2-5 Welch, 1967, Use of fast Fourier transform for estimation of power spectra – a method based on time averaging over short modified periodograms, IEEE Trans Audio Electroacoust, AU15, 70, 10.1109/TAU.1967.1161901 Westad, 2003, Motor unit recruitment and derecruitment induced by brief increase in contraction amplitude of the human trapezius muscle, J Physiol (Lond), 552, 645, 10.1113/jphysiol.2003.044990 Westgaard, 1999, Motor unit substitution in long-duration contractions of the human trapezius muscle, J Neurophysiol, 82, 501, 10.1152/jn.1999.82.1.501