caa a22 4500 467941416 CHVBK 20180406153013.0 cr unu---uuuuu 170328e20060101xx s 000 0 eng 10.1007/s00421-004-1291-2 doi (NATIONALLICENCE)springer-10.1007/s00421-004-1291-2 Comparison of the electromyographic activity in the upper trapezius and biceps brachii muscle in subjects with muscular disorders: a pilot study [Elektronische Daten] [E. Schulte, L. Kallenberg, H. Christensen, C. Disselhorst-Klug, H. Hermens, G. Rau, K. Søgaard] The aim of the present study was to investigate the extent to which work-related muscular disorders of the upper trapezius affect the activity of other pain-free muscles, in particular in the biceps brachii. Two groups of female subjects (age >43 years) participated in the study: seven affected subjects with self-reported disorders in the shoulder/neck region (cases) and nine healthy subjects (control group). Multi-channel electromyography (EMG) and force were recorded during maximum voluntary contractions (MVC) and during 6min sustained contractions (at 30% MVC) of the upper trapezius and biceps brachii on the dominant side. From the EMG signals, the root mean square (RMS), median frequency (MDF) and single motor unit (MU) conduction velocity (CV) were estimated. From the force signal, the coefficient of variation was calculated. All data are presented as mean values and standard deviation. Differences between the cases and controls were found in the MVC force of the upper trapezius, which was lower in cases [253 (70)N] than in controls [357 (75)N], while the coefficient of variation of force during the sustained contraction was increased [cases 5.5 (2.2); controls 4.1 (1.9)]. The RMS (normalized to the RMS at MVC) during the 6min sustained contractions was significantly lower in the cases than in the controls for both the upper trapezius and the biceps brachii. A tendency towards a smaller increase in the RMS with fatigue was only found in the trapezius muscle [slope: cases 6.5 (14.1)%/min, controls 10.2 (12.9)%/min]. No differences were found between the two subject groups with respect to the MDF and single MU CV in both muscles. While the lower RMS for the trapezius muscles of the cases may reflect changes at the local level, as well as in motor control, the lower biceps activity indicates a change in the central control strategies of the primarily unaffected muscle. Indications for a changed fatigability of the muscle were only found in the trapezius. Springer-Verlag, 2005 Biceps brachii nationallicence Fatigue nationallicence Isometric contraction nationallicence Surface electromyography nationallicence Trapezius myalgia nationallicence Schulte E. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut Kallenberg L. Roessingh Research and Development, Enschede, The Netherlands aut Christensen H. National Institute of Occupational Health, Copenhagen, Denmark aut Disselhorst-Klug C. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut Hermens H. Roessingh Research and Development, Enschede, The Netherlands aut Rau G. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut Søgaard K. National Institute of Occupational Health, Copenhagen, Denmark aut European Journal of Applied Physiology Springer-Verlag 96/2(2006-01-01), 185-193 1439-6319 96:2<185 2006 96 421 https://doi.org/10.1007/s00421-004-1291-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-004-1291-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schulte E. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut NATIONALLICENCE 700 1- Kallenberg L. Roessingh Research and Development, Enschede, The Netherlands aut NATIONALLICENCE 700 1- Christensen H. National Institute of Occupational Health, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Disselhorst-Klug C. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut NATIONALLICENCE 700 1- Hermens H. Roessingh Research and Development, Enschede, The Netherlands aut NATIONALLICENCE 700 1- Rau G. Helmholtz Institute, Chair for Applied Medical Engineering, Aachen, Germany aut NATIONALLICENCE 700 1- Søgaard K. National Institute of Occupational Health, Copenhagen, Denmark aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/2(2006-01-01), 185-193 1439-6319 96:2<185 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer