caa a22 4500 469054344 CHVBK 20180323132839.0 cr unu---uuuuu 170328e19920501xx s 000 0 eng 10.1007/BF00705090 doi (NATIONALLICENCE)springer-10.1007/BF00705090 Electromyographic changes in work-related myalgia of the trapezius muscle [Elektronische Daten] [Tommy Öberg, Leif Sandsjö, Roland Kadefors, Sven-Erik Larsson] Summary: In 11 patients, all women, 21-55 years of age, with unilateral work-related myalgia of the trapezius muscle, the right and left trapezius muscles were examined simultaneously for electromyogram (EMG) signs of localized muscle fatigue. All patients were tested with 0-kg hand load for 5 min, holding the arms straight at 90° of elevation in the scapular plane. Only 4 of the patients tolerated exposure to higher load levels. They were tested with 1 kg hand load for 3 min and 2 kg hand load for 2 min, with a period of rest of 30 min between the trials. The EMG mean power frequency (MPF) and root mean square (rms) were calculated. Data were normalized with the initial value as a reference and regression analyses were performed. On both sides a decrease of MPF and an increase of rms were found with increasing time and load, i.e. classical EMG signs of localized muscle fatigue. Compared with the nonaffected side smaller changes were found on the affected side, possibly due to pain inhibition, impaired microcirculation and biochemical changes along the muscle fibres. At 0-kg hand load we found no change of MPF on either side despite subjective feelings of fatigue and pain. We interpreted these findings as an indication of reduced capacity of the affected trapezius muscle to sustain static load with early development of pain-associated local fatigue. Springer-Verlag, 1992 Electromyogram nationallicence Amplitude nationallicence Frequency nationallicence Fatigue nationallicence Shoulder pain nationallicence Trapezius muscle nationallicence Öberg Tommy Department of Biomechanics, University College of Health Sciences, P.O. Box 1038, S-55111, Jönköping, Sweden aut Sandsjö Leif Department of Applied Electronics, Chalmers University of Technology, Göteborg, Sweden aut Kadefors Roland Department of Applied Electronics, Chalmers University of Technology, Göteborg, Sweden aut Larsson Sven-Erik Department of Orthopaedics, University of Linköping, Sweden aut European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/3(1992-05-01), 251-257 0301-5548 65:3<251 1992 65 421 https://doi.org/10.1007/BF00705090 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00705090 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Öberg Tommy Department of Biomechanics, University College of Health Sciences, P.O. Box 1038, S-55111, Jönköping, Sweden aut NATIONALLICENCE 700 1- Sandsjö Leif Department of Applied Electronics, Chalmers University of Technology, Göteborg, Sweden aut NATIONALLICENCE 700 1- Kadefors Roland Department of Applied Electronics, Chalmers University of Technology, Göteborg, Sweden aut NATIONALLICENCE 700 1- Larsson Sven-Erik Department of Orthopaedics, University of Linköping, Sweden aut NATIONALLICENCE 773 0- European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/3(1992-05-01), 251-257 0301-5548 65:3<251 1992 65 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer