Does local immersion in thermo-neutral bath influence surface EMG measurements? Results of an experimental trial.

Authors: Kalpakcioglu B (1) , Candir F (2) , Bernateck M (3) , Gutenbrunner C (2) , Fischer MJ (2)
(1) Department of Physical Therapy and Rehabilitation, Haydarpasa Numune State Hospital (2) Department of Physical Medicine and Rehabilitation, Medical School of Hanover (3) Department of Anesthesiology, Pain Clinic, Hanover Medical School
Source: J Electromyogr Kinesiol. 2009 Dec;19(6):e550-3
DOI: 10.1016/j.jelekin.2008.09.006 Publication date: 2009 Dec E-Publication date: Nov. 22, 2008 Availability: abstract Copyright: © 2008 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
Language: English Countries: Not specified Location: Not specified Correspondence address: Fischer MJ :


Article abstract

This study investigated the effect of water immersion on surface electromyography (EMG) signals recorded from the brachioradial muscle of 11 healthy subjects, both in a dry environment and a thermo-neutral forearm bath (36 degrees C). EMG measurements were registered in a sitting position, using waterproof electrodes under 3 conditions: relaxed muscle, maximum voluntary isometric contraction (MVC, 1s, grip test) and 70% of the MVC (5 s). In relaxed muscle, mean EMG values were significantly higher under immersion compared to the dry conditions (dry: 5.4+/-3.6 microV; water: 19.5+/-14.9 microV; p=0.014). In maximum voluntary isometric contraction, there was a significant difference, though not in the same direction (dry: 145.9+/-58.9 microV; water: 73.2+/-35.0 microV; p=0.003). Under 70% MVC, there was no difference between wet and dry conditions (dry: 102.4+/-75.0 microV; water: 100.4+/-65.3 microV; p=0.951). Results suggest that dry and underwater conditions influence EMG readings; however, the results are inconsistent. These findings indicate additional influences on resting muscle activity, as well as MVC. Further measurements with other muscle groups and different types of immersion are needed to clarify conflicting observations.

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