Temperature dependency of turn/amplitude parameters

Abstract

Objectives: to assess the influence of the skin and muscle temperatures on the turns per second (T/s) and the amplitude per turn (A/T) and to find out whether turn /amplitude analysis requires temperature monitoring. Subjects: ten healthy individuals (three women, seven men) aged 23 to 36 years. Method: recording of two electromyograms (EMGs) in the right biceps brachii muscle from ten locations each, during isometric contractions with 30% of the elbow flexors′ maximum force. The first EMG was recorded after warming the muscle to at least 37° C and the second EMG after cooling the muscle to at least 27° C. Results: lowering the muscle temperature by an average of 10.9° C, the mean T/s decreased from 484 to 436 (P =0.002), the mean A/T increased from 476 to 513 (P =NS) and the mean ratio T/s:A/T decreased from 1.1 to 0.91 (P = 0.0001). None of the individual results became patholgical after cooling the muscle. Conclusion: in a range of 27 to 37° C, turn/amplitude analysis can be performed without temperature monitoring.