English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

[Purpose] The purpose of this study was to examine the influence of the cervical flexion angle when using a smart phone on muscle fatigue of the cervical erector spinae (CES) and upper trapezius (UT). [Subjects] This study recruited 12 healthy adults. [Methods] Each subject sat on a chair, with his/her back against the wall and held a smart phone with both hands. Fatigue of the neck and shoulder muscles at different cervical flexion angles (0°, 30°, and 50°) was measured by electromyography. The following muscles were assessed: the right upper trapezius (RtUT), left upper trapezius (LtUT), right cervical erector spinae (RtCES), and left cervical erector spinae (LtCES). A cervical range of motion instrument was attached to the subjects' heads to measure the cervical angle during the experiment. [Results] The RtUT and LtUT showed the highest muscle fatigue at a cervical flexion angle of 50° and the lowest fatigue at an angle of 30°. There was no significant difference in the muscle fatigue of the RtCES and LtCES at any of the cervical flexion angles. [Conclusion] UT muscle fatigue depends on the cervical flexion angle when using a smart phone.

Effect of the cervical flexion angle during smart phone use on muscle fatigue of the cervical erector spinae and upper trapezius