Investigating motor fatigue using force, EMG, and kinematic data

This study is a within-subject design comprising 30 subjects. Each subject performed three rounds of: Maximum Voluntary Contraction (MVC) 3×, Fatiguing Task (FT), MVC 1×, BORG-CR10, Assessment Task (AT), and a recovery period. The only difference between the three rounds was the level of force intensity (5%, 50% or 75% of MVC) during the FT. Electromyography (EMG) of the right and left flexor carpi radialis (FCR) and extensor carpi radialis longus (ECR) muscles was acquired using bipolar configuration with a TMSi Porti7 recorder (Twente Medical Systems International B.V., Oldenzaal, The Netherlands). Small adhesive disposable electrodes with a contact area of 4.5 cm2 (Kendall H124SG; Cardinal Health, Dublin, OH, USA) were used, and placed in a bipolar setup with two electrodes placed next to each other on the bulk of the muscle belly at a fixed distance of 24 mm between the centres of the electrodes. A common grounding electrode was placed on the ulnar styloid process. EMG signals were recorded in raw format at a sampling rate of 2048 Hz and were routed through LSL and LabRecorder.Force data were recorded using a hand dynamometer (Biopac Systems Inc., Aero Camino Goleta, CA, USA) and custom code (https://github.com/cathazi/task-Fatigue.git) implemented in MATLAB R2022a (The MathWorks Inc., Natick, MA, USA) using the Psychophysics Toolbox extensions (Psychtoolbox-3). Force data were sampled at 47.75 Hz. Dynamometer force data were routed through Lab Streaming Layer (LSL) and LabRecorder (https://github.com/labstreaminglayer/App-LabRecorder).Kinematic data were acquired using a Kinarm End-Point Lab robot with Dexterit-E 3.9.2 software (BKIN Technologies Ltd., Kingston, ON, Canada). For MVC Force and EMG data are available in .xdf files.For AT Kinarm data are available in .kinarm files and EMG data are available in .xdf files.  Each subject folder contains 20 files:SXX_calibration_MVC_1.* - mat & xdfSXX_calibration_MVC_3.* - mat & xdfSXX_calibration_MVC_offset.* - mat & xdf SXX_Fat_TY_ZZ.* - mat & xdf, whereby Y could be 1,2, or 3 indicating the round, and ZZ could be 5, 50, or 75 indicating the fatigue level. Each file contains data for MVC 3, FT, and MVC 1.SXX_Kin_Baseline.* - xdf & kinarmSXX_Kin_TY_ZZ.* - xdf & kinarm, whereby Y could be 1,2, or 3 indicating the round, and ZZ could be 5, 50, or 75 indicating the fatigue level. Each file contains data for AT. For details of the MVC, FT, and AT please see the preprint: https://doi.org/10.1101/2024.12.01.626257  In addition, the following Questionnaire data were obtained: AGQ-S = Achievement Goals Questionnaire for SportBIMAN = Bimanual Tasks in Daily Life QuestionnaireBORG = BORG-CR10 rating scaleEHI = Edinburgh Handedness InventoryGPAQ = WHO Global Physical Activity Questionnaire