Gender effects on the coordination of subdivisions of the trapezius muscle during a repetitive box-folding task

Abstract

This study aimed at investigating gender difference in the coordination of the subdivisions of the trapezius muscle during a repetitive box-folding movement task. Twenty-two healthy volunteers (11 males and 11 females) performed the repetitive box-folding task for 34 min. During the task, perceived exertion and surface electromyographic (EMG) signals from the upper, middle, and lower trapezius subdivisions were recorded. Absolute and normalised root mean square (RMS) values as well as normalised mutual information (NMI) values were calculated to assess, respectively, activation levels within muscle subdivisions and functional connectivity among subdivisions. Females compared with males were characterised by higher normalised RMS values in the upper trapezius (P < 0.05) and higher NMI values within the upper-middle subdivision pair (P < 0.05) during repetitive box-folding. The elevated normalised level of activation of the upper trapezius as well as the enhanced functional connectivity among upper-middle trapezius subdivisions underlined that females adopted a different motor strategy than males did during a dynamic repetitive task. Such differences within and among muscle subdivisions may not be a favourable trait and could partly contribute to the higher prevalence of musculoskeletal disorders reported in females.

Cervical flexion–relaxation response to neck muscle fatigue in males and females

“…This produced a higher FRR among females than males. Higher neck and shoulder muscle activation in females compared to males was also observed in a few previous studies (Johansen et al, 2013;Nordander et al, 2008). Lindman et al (1991) reported that females possess lower functional capacity due to a smaller cross-sectional fiber area.…”

Computer work and self-reported variables on anthropometrics, computer usage, work ability, productivity, pain, and physical activity

“…More studies elaborating on pain mechanisms using quantitative sensory testing among computer users [53] are needed to obtain a more profound understanding of the WMSD [1]. Issues related to ergonomics, i.e., working posture and motor control were not addressed even though these are known to play a role in the gender differences found in WMSD [18,54-56]. Thus, confounding factors related to uncontrolled ergonomic, psychosocial, and personal factors cannot be excluded.…”

Social Motor Coordination in Unaffected Relatives of Schizophrenia Patients: A Potential Intermediate Phenotype

“…To create dyads for testing social coordination, the 27 first-degree relative participants and the 27 matched control participants were randomly paired with 54 unmatched healthy partners. All partner pairs were of the same sex to avoid methodological bias (Katic et al, 2012, 2013; Johansen et al, 2013). But, note that although 54 healthy partners were unmatched on the age, level education, and premorbid IQ with the relatives and controls, they were matched between them (see Table 1).…”