Muscle Fatigue Revisited - Insights From Optically Pumped Magnetometers

Davide Sometti; Lorenzo Semeia; Sangyeob Baek; Hui Chen; Giulia Righetti; Juergen Dax; Cornelius Kronlage; Milena Kirchgässner; Alyssa Romano; Johanna Heilos; Deborah Staber; Julia Oppold; Thomas Middelmann; Christoph Braun; Philip Broser; Justus Marquetand

doi:10.3389/fphys.2021.724755

Muscle Fatigue Revisited - Insights From Optically Pumped Magnetometers

Front Physiol. 2021 Dec 17:12:724755. doi: 10.3389/fphys.2021.724755. eCollection 2021.

Authors

Davide Sometti^{1

2

3

4}, Lorenzo Semeia^{3

5}, Sangyeob Baek^{1

2}, Hui Chen^{1

2}, Giulia Righetti^{1

2

3

6}, Juergen Dax^{1

2}, Cornelius Kronlage⁷, Milena Kirchgässner⁷, Alyssa Romano⁷, Johanna Heilos⁷, Deborah Staber⁷, Julia Oppold⁷, Thomas Middelmann⁸, Christoph Braun^{1

2

9

10}, Philip Broser¹¹, Justus Marquetand^{1

2

7}

Affiliations

¹ Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
² MEG-Center, University of Tübingen, Tübingen, Germany.
³ Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tübingen, Tübingen, Germany.
⁴ Center for Pediatric Clinical Studies, University of Tübingen, Tübingen, Germany.
⁵ German Center for Diabetes Research (DZD), IDM/fMEG Center of the Helmholtz Center Munich at the University of Tübingen, University of Tübingen, Tübingen, Germany.
⁶ Center for Ophthalmology, University of Tübingen, Tübingen, Germany.
⁷ Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
⁸ Department of Biosignals, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany.
⁹ Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy.
¹⁰ Department of Psychology and Cognitive Science (DiPsCo), University of Trento, Rovereto, Italy.
¹¹ Children's Hospital of Eastern Switzerland, Sankt Gallen, Switzerland.

Abstract

So far, surface electromyography (sEMG) has been the method of choice to detect and evaluate muscle fatigue. However, recent advancements in non-cryogenic quantum sensors, such as optically pumped magnetometers (OPMs), enable interesting possibilities to flexibly record biomagnetic signals. Yet, a magnetomyographic investigation of muscular fatigue is still missing. Here, we simultaneously used sEMG (4 surface electrode) and OPM-based magnetomyography (OPM-MMG, 4 sensors) to detect muscle fatigue during a 3 × 1-min isometric contractions of the left rectus femoris muscle in 7 healthy participants. Both signals exhibited the characteristic spectral compression distinctive for muscle fatigue. OPM-MMG and sEMG slope values, used to quantify the spectral compression of the signals, were positively correlated, displaying similarity between the techniques. Additionally, the analysis of the different components of the magnetic field vector enabled speculations regarding the propagation of the muscle action potentials (MAPs). Altogether these results show the feasibility of the magnetomyographic approach with OPMs and propose a potential alternative to sEMG for the study of muscle fatigue.

Keywords: OPM; magnetomyography; muscle fatigue; quantum sensors; sEMG.