Force Increase in a Repetitive Motor Task Inducing Motor Fatigue

Abstract

To evaluate task induced motor fatigue in a well-established finger tapping task, we analyzed tapping parameters and included the time course of measures of force. We hypothesized that a decline in tapping force would reflect task induced motor fatigue, defined by a lengthening of inter-tap intervals (ITI). A secondary aim was to investigate the reliability of tapping data acquisition with the force sensor. Results show that, as expected, tapping speed decreased linearly over time, due to both an increase of ITI and tap duration. In contrast, tapping force increased non-linearly over time and was uncorrelated to changes in tapping speed. Force data could serve as a measure to characterize task induced motor fatigue. Force sensors can assess a decline in tapping speed as well as an independent increase of tapping force. We argue that the increase of force reflects central compensation, i.e. perception of fatigue, due to an increase in task effort and difficulty.

Keywords:

• finger tapping
• force
• motor fatigue
• motor performance

Acknowledgments

All authors have materially participated in research/article preparation, experimental setup and project conduction and/or manuscript preparation and data analysis. All authors have approved the final article.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the DFG (Deutsche Forschungsgemeinschaft; Grant number: BR 1691/8-1).