Analysis of the electromyographic activity, strength, and heart rate variability in caregivers of bedridden patients before and after a workday: a cross-sectional observational study

This study aims to analyze the electromyographic (EMG) signal and strength of the erector spinae muscles and heart rate variability (HRV) of caregivers before and after a workday. Twenty-four caregivers with low back pain were selected. EMG data (RMS (Root Mean Square) and F50) and erector spinae strength were collected from three maximal voluntary isometric contractions and recorded using an electromyograph (EMG System of Brazil 830C). HRV was collected using the POLAR H10 strap. For data analysis, GraphPad Prism (version 8.4; GraphPad Software, Inc.) was used, and the significance level was set at 5%. RMS significantly increased after a workday, but no significant drop was observed in the values of F50 and strength. Regarding HRV, a predominance of the sympathetic nervous system was observed to the detriment of the parasympathetic nervous system. The results suggest increased neuromuscular demand and autonomic alterations consistent with higher physiological stress at the end of the day.