Comparison of the electromyographic activity in the upper trapezius and bicepts brachii muscle in subjects with muscular disorders: a pilot study

Share/Save/Bookmark

Schulte, E. and Kallenberg, L.A.C. and Christensen, H. and Disselhorst-Klug, C. and Hermens, H.J. and Rau, G. and Sogaard, K. (2006) Comparison of the electromyographic activity in the upper trapezius and bicepts brachii muscle in subjects with muscular disorders: a pilot study. European Journal of Applied Physiology, 96 (2). pp. 185-193. ISSN 1439-6327

[img] PDF
Restricted to UT campus only
: Request a copy
284kB
Abstract: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 6 min 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 6 min 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.
Keywords Biceps brachii - Fatigue - Isometric contraction
Item Type:Article
Copyright:© 2006 Springer-Verlag
Faculty:
Electrical Engineering, Mathematics and Computer Science (EEMCS)
Research Group:
Link to this item:http://purl.utwente.nl/publications/63772
Official URL:http://dx.doi.org/10.1007/s00421-004-1291-2
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page

Metis ID: 237733