Data for: Intermuscular Coherence between Surface EMG Signals recorded with Monopolar and Bipolar EMG Systems during Squatting
This dataset contains raw EMG / goniometer data as well as a processed data sheet from a study with the research question how different EMG recording techniques affect the intermuscular coherence between surface EMG signals. It was hypothesized that bipolar EMG signals would show a lower EMG-EMG coherence compared to monopolar signals due to inevitable errors in electrode alignment when aligning the sensors with the muscle fiber direction. 16 participants (12 male, 4 female, young, active adults) are included in this analysis. The muscles investigated were vastus lateralis and medialis and the investigated movement tasks were series of bipedal squats for 90 seconds (first trial stable on the ground, second trial stable on the ground, third trial unstable on a BOSU ball. The main findings are that the intermuscular coherence between vastus lateralis and medialis was indeed reduced in the bipolar compared to monopolar recordings. Furthermore, coherence below 40 Hz was increased during unstable squatting and the monopolar current and bipolar potential systems were most sensitive to this change while the monopolar potential recordings showed low sensitivity. Content of files: 1) "2018-04-EMG-EMG intermuscular coherence and EMG intensities" contains an Excel file with all averages across squats and subjects for each of the recording systems. 2) "Raw Data" contains a Matlab .mat file with the raw EMG data from each system and goniometre data representing the corresponding knee flexion angle during squatting. The .mat file contains a cell array with 16 cells, one for each subject. The subject-specific cells contain a 3x3 cell array, rows for recording systems (bipolar potential, monopolar potential, monopolar current), columns for trials (stable squatting 1, stable squatting 2, unstable squatting). Each cell contains three data columns (VL EMG, VM EMG, goniometer data in Voltage).