Repeatability of electromyography normalization of the neck and shoulder muscles in symptomatic office workers
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Published on: September 13, 2015
Montakarn Chaikumarn1, Nuttika Nakphet2, Prawit Janwantanakul1
1a Faculty of Allied Health Sciences , Chulalongkorn University , Thailand.
Purpose:
The purpose of the study was to examine the repeatability of electromyography (EMG) normalization in office workers with neck and shoulder symptoms.
Methods:
Fifteen female office workers with neck/shoulder symptoms were recruited to participate in two separate days of testing. Maximum voluntary isometric contraction (MVIC) was used for the normalization of EMG data on the following muscles: cervical erector spinae, upper trapezius, lower trapezius and anterior deltoid. Repeatability was calculated using the intra-class correlation (ICC), relative standard error of measurement (%SEM) and relative coefficient of variation (%CV).
Results:
Peak root mean square (rms) and median frequency (MF) showed good to high repeatability in the UT, AD and CES (ICC = 0.87-0.95, %SEM= 2.65-9.48, %CV= 0.2-5.9). The repeatability of peak rms was good (ICC = 0.87, %SEM = 12.56, %CV = 3.3) and the MF of the LT was fair (ICC = 0.76, %SEM = 5.71, %CV = 2.9).
Conclusion:
Peak rms and MF from the MVIC normalization method can be measured with sufficient repeatability in symptomatic office workers.
