Does sEMG normalization change results on sex differences in the activation of the shoulder girdle muscles during a simulated work task?

Author(s)

Cid, Marina Machado ^[1] ; Januario, Leticia Bergamin ^{[1, 2]} ; Carreira Moreira, Roberta de Fatima ^[1] ; Cote, Julie N. ^[3] ; Madeleine, Pascal ^[4] ; Oliveira, Ana Beatriz ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Phys Therapy, Lab Clin & Occupat Kinesiol LACO, Rodovia Washington Luis, Km 235, SP-310, Sao Carlos, SP - Brazil

^[2] Univ Gavle, Ctr Musculoskeletal Res, Dept Occupat Hlth Sci & Psychol, Kungsbacksvagen 47, S-80176 Gavle - Sweden

^[3] McGill Univ, Dept Kinesiol & Phys Educ, 475 Pine Ave West, Montreal, PQ H2W 1S4 - Canada

^[4] Aalborg Univ, Dept Hlth Sci & Technol, Sport Sci Performance & Technol, Niels Jernes Vej 12, DK-9220 Aalborg - Denmark

• Document type: Journal article
• Source: APPLIED ERGONOMICS; v. 85, MAY 2020.
• Web of Science Citations: 0

Abstract

The aim was to investigate if the method of normalizing surface electromyography (sEMG) can change results on sex differences in the muscular activation of the shoulder girdle muscles during a simulated work task. sEMG was recorded in 36 asymptomatic participants (17 females, 19 males) from four parts of trapezius and from serratus anterior muscles during a simulated work task. Four normalization methods, one involving maximal voluntary contractions (MVCs) and three involving submaximal voluntary contractions were applied. Sex differences in absolute and normalized amplitude of sEMG were analyzed. The normalization method had a significant influence on the observed sex differences. Females only showed higher sEMG amplitude than males when the sEMGs were normalized to MVC and to a submaximal contraction based on 20% of MVC for the upper trapezius (acromial fibers). Researchers and practitioners should be aware of the impact of the sEMG normalization method in sex differences investigation. (AU)

• FAPESP's process: 16/22386-6 - Effect of gender and normalization of sEMG on the activation of trapezius and serratus muscles during repetitive working task
• Grantee: Ana Beatriz de Oliveira
• Support Opportunities: Regular Research Grants