کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4065446 | 1266252 | 2009 | 7 صفحه PDF | دانلود رایگان |
This study investigated the feasibility of measuring voluntary activation of the trapezius muscle with twitch interpolation. Subjects (n = 8) lifted the right shoulder or both shoulders against fixed force transducers. Stimulation of the accessory nerve in the neck was used to evoke maximal twitches in right trapezius. The twitch-like increments in force (superimposed twitches) evoked during different strength voluntary contractions were linearly related to voluntary force (r = −0.82 to −0.99). Hence, voluntary activation could be quantified by twitch interpolation with this stimulus. Comparison of unilateral and bilateral MVCs showed that maximal voluntary force was greater in unilateral than bilateral efforts (92.7 ± 2.9% and 82.3 ± 5.8% MVC, respectively) but voluntary activation was similar (88.6 ± 9.6% and 91.7 ± 5.2%). Trapezius is commonly affected in work-related musculoskeletal disorders. Measurement of voluntary activation will be a useful technique to demonstrate whether the reduced maximal voluntary force reported in such disorders is due to muscular or neural factors.
Journal: Journal of Electromyography and Kinesiology - Volume 19, Issue 4, August 2009, Pages 584–590