Calibrating ratings of perceived fatigue relative to objective measures of localised muscle fatigue using a feedback-based familiarisation protocol

Abstract

Localized muscle fatigue (LMF) manifests as a reduction in muscle force generating capacity, an increase in electromyography signal amplitude and a decrease in mean power frequency (MnPF). Estimates of LMF can also be obtained subjectively through ratings of perceived fatigue (RPF); however, the provision of RPF scale familiarisation is inconsistent within the literature. The purpose of this study was to explore the effect of an RPF familiarisation session on the accuracy of RPF, relative to objective measures of fatigue, during a LMF protocol. Twenty participants performed intermittent isometric elbow flexion efforts to fatigue. Following each 5-minute cycle, RPF ratings were provided using a visual analog scale, and an MVC was obtained. On day 2, the ‘feedback’ group received visual feedback pertaining to their reduction in MVC, immediately following their RPF input, while the control group received no feedback. On day 3 (retention), RMSE was 72% lower between RPF and MVC, and 69% lower between RPF and MnPF for the feedback group after the familiarisation period. Findings support the inclusion of a familiarisation session to improve RPF as a surrogate measure for traditional objective measures of LMF.

Keywords:

• Ratings of perceived fatigue
• muscle fatigue
• psychophysics
• electromyography

Disclosure statement

The authors declare they have no conflict of interest.

Financial disclosure statement

The authors stand to gain no financial benefit from this work.

Additional information

Funding

This work was supported by the Centre of Research Expertise for the Prevention of Musculoskeletal Disorders (CRE-MSD) seed grant program.

Notes on contributors

Daniel M. Abdel-Malek

Daniel M. Abdel-Malek received his Bachelor and Master’s of Health Sciences degrees at Ontario Tech University in 2017 and 2019, respectively. He began medical school at Dalhousie University in Fall 2019.

Ryan C. A. Foley

Ryan C.A. Foley received his Bachelor of Science and Master of Science degrees in Kinesiology (neurophysiology) from Wilfrid Laurier University in 2012 and 2015, respectively. Currently, he is the Kinesiology Laboratory Specialist, sessional instructor and Doctoral student in the Faculty of Health Sciences at Ontario Tech University.

Fahima Wakeely

Fahima Wakeely received her Bachelor of Health Sciences degree from Ontario Tech University in 2019. She is currently a Master’s student at Ontario Tech University with a focus in biomechanics and ergonomics.

Jeffrey D. Graham

Jeffrey D. Graham received his Bachelor of Arts in Kinesiology (Honors Specialization) and Psychology (Major) at Western University in 2009, followed by his MSc (2011) and PhD (2015) in Kinesiology (Exercise and Health Psychology) from McMaster University. He is currently a postdoctoral fellow in the Department of Family Medicine at McMaster University.

Nicholas J. La Delfa

Nicholas J. La Delfa received his B.Sc.kin (2009), MSc (2011) and PhD (2016) degrees in Kinesiology (biomechanics/ergonomics) from McMaster University, followed by a post-doctoral fellowship at the University of Waterloo. He is currently an Assistant Professor in the Faculty of Health Sciences at Ontario Tech University.