Personal Protective Equipment Alters Leg Muscle Fatigability Independent of Transcranial Direct Current Stimulation: A Comparison with Pre-COVID-19 Pandemic Results.

Alexandra C Fietsam,Justin R Deters,Thorsten Rudroff,Craig D Workman

doi:10.3390/brainsci11080962

Alexandra C Fietsam, Justin R Deters + Show 2 more

Open Access

https://doi.org/10.3390/brainsci11080962

Copy DOI

Journal: Brain sciences	Publication Date: Jul 22, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: University of Iowa

Abstract

In response to the COVID-19 pandemic, the use of personal protective equipment (PPE; e.g., face mask) has increased. Mandating subjects to wear PPE during vigorous exercise might affect the fatigue outcomes of transcranial direct current stimulation (tDCS) studies. The purpose of this study was to investigate whether the use of PPE affected the performance of a tDCS-influenced fatigue task in healthy adults. A total of 16 young and healthy subjects were recruited and wore PPE during an isokinetic fatigue task in conjunction with sham, 2 mA, and 4 mA tDCS conditions. Subjects were matched to subjects who did not wear PPE during our previous pre-pandemic study in which right knee extensor fatigability increased under these same conditions. The results show that right knee extensor fatigability, derived from torque and work (FI-T and FI-W, respectively), was higher in the PPE study compared to the No PPE study in the sham condition. Additionally, there were no differences in knee extensor fatigability or muscle activity between sham, 2 mA, and 4 mA tDCS in the present study, which contrasts with our previous results. Thus, PPE worn by subjects and researchers might have a detrimental effect on fatigue outcomes in tDCS studies irrespective of the stimulation intervention.

Highlights

Consistent with our previous protocols, the current study evaluated the effects of 2 mA and 4 mA M1 transcranial direct current stimulation (tDCS) on the performance of an isokinetic fatigue test of the knee extensors in a sample of young, healthy subjects while the subjects wore protective equipment (PPE)
We hypothesized that wearing PPE would significantly increase the subjects’ fatigue profile compared to the data collected on subjects without PPE from our previous studies [5,6] independent of the tDCS intensity
All subjects completed the study, and out of the 16 subjects recruited for the current study and 16 subjects from our previous study (No PPE; [6]), none had FI results below the FI bias correction cut-off (FI ≤ 0%; indicating torque production was higher at the end compared to the beginning of the fatigue task (FT))

Summary

Introduction

E.g., face mask, face shield) has risen to reduce the spread of the virus. In human subject research, wearing PPE during vigorous motor function tests is important to prevent the spread of infectious respiratory droplets [1]. The ability to perform motor function tests, such as fatiguing exercises, while wearing PPE is potentially problematic because it may alter the study outcomes by decreasing the amount of oxygen available and/or increasing air trapping, which may reduce carbon dioxide exchange [2]. The resulting hypercapnic hypoxia postulated by Chandrasekaran and Fernandes (2020) may induce an acidic environment in the alveoli or blood and increase cardiac overload, anaerobic metabolism, and renal overload [2], all of which might worsen the underlying pathologies of frequently studied chronic diseases

Objectives

Methods

Results

Conclusion