The Impact of Chronic Neck Pain on the Evolution of Superficial Neck Muscle Fatigue in Women

This study aims to investigate the differences in muscle fatigue evolution during sustained neck exertion between patients with chronic neck pain (CNP) and healthy controls. Muscles gradually enter a state of fatigue during continuous contraction, which is reflected in the surface electromyography (sEMG) as an increase in signal amplitude and a decrease in frequency. Although the general trend of muscle fatigue is a common characteristic, there are differences in fatigue properties among different muscles, and the specific fatigue evolution characteristics in the neck muscles of CNP patients remain unclear. We conducted a case-control study to analyze the distribution differences of sEMG characteristics of neck muscles at different time points. The results indicated that during sustained muscle exertion, the root mean square (RMS) increased and the mean power frequency (MPF) decreased over time, with statistically significant differences from the initial values, suggesting that the muscles had entered a state of fatigue. By comparing the fatigue characteristics and the timing of fatigue onset between the healthy and CNP groups, this study identified significant differences in muscle fatigue evolution between the two groups, providing important insights into the potential physiological mechanisms underlying CNP.