Background and rationale {6a}
The employees are used to spending long periods of time in front of a computer with a dorsiflexed posture [
1], in fact requiring high concentration and focus while working with a computer causes them not to pay attention to the body position. This lack of awareness of the body posture is one of the important reasons for poor posture among office workers [
2].
Poor posture can change physiological, structural, physical, and functional aspects; furthermore, it can affect learning and attention [
3]. For instance, slump posture decreases the rate of speaking compared to sitting upright [
4] and slouched posture makes it difficult to do a math test [
5]. According to Lee et al.’s study, forward head posture negatively influences the state of rest and concentration of the brain, as measured by a neuro-feedback system [
6]. Based on these studies, it can be expected that poor posture causes or aggravates mental fatigue.
Mental fatigue is defined by feeling sleepy and drowsy while needing to concentrate [
7] and has indicators such as feeling tired, a decrease in energy [
8], mood changes [
9], a decrease in performance, a decrease in accuracy and an increase in reaction time [
9,
10], as well as changes in brain activity [
7]. Mental fatigue has a negative impact not only on task performance in different environments, such as school [
11] and workplace [
12], but also on the safety of people [
13]. For example; the risk of fatigue-related accidents increases, when employees get stuck in traffic after a long work day [
14]. In some cases, such as those of industry workers, surgeons, drivers, and pilots, mental fatigue can lead to many hazards that cause both economic and human losses [
12,
15]. Considering the high prevalence of mental fatigue in everyday modern life, it is necessary to search for efficient interventions to improve task productivity and occupational health. To date, the number of studies on tackling mental fatigue is fairly limited [
16].
Exercise and physical activity have been considered as interventions for improving mental fatigue. These interventions increase the performance of the prefrontal cortex, which includes attention, memory, problem-solving, and decision-making [
17]. For example, performing targeted stretching micro-breaks in surgeons without increasing the surgery time, improved their performance and concentration [
18]. Furthermore, a short-term supervised exercise program including stretching exercises and joint mobility during a work shift has been shown to be more efficient than rest for reducing mental fatigue [
19].tDCS is a type of non-invasive electrical stimulation that can change neural excitability in the cortex [
20,
21]. tDCS can improve cognitive function in both healthy individuals and neurological patients [
22,
23]. According to studies, anodal stimulation enhances learning, memory, and attention [
24]. The effect of tDCS has been compared with caffeine as the most common habit to reduce fatigue. Interestingly, tDCS has a greater effect on attention and this effect also lasts longer (6 h) than caffeine (2 h) [
25].
A limited number of studies have investigated the non-biomechanical part of poor posture. Most of these articles have used functional tests (such as rate of speaking) to investigate the impact of poor posture, and only one article has examined the correlation between forward head posture and brain signals as measured by a neuro-feedback system [
6]; At present, there is an absence of studies utilizing QEEG to track mental fatigue in slump sitting, and in addition, the potential role of slump posture on work productivity needs to be investigated. Given the negative mental state consequences associated with poor posture and the high prevalence of slump sitting, there is a critical need to investigate changes in cortical activity and task productivity in this posture. Previous studies indicate that tDCS and stretching exercises can reduce the adverse effect of mental fatigue, however; no study has compared the effect of transcortical stimulation and stretching exercises in improving mental fatigue with neurophysiological markers of electroencephalography.
In this study, we will be trying to take a more comprehensive look at posture and assess its central aspect using brain data obtained from electroencephalography. Also, another aim of the study will be to investigate and compare the effects of transcortical stimulation and stretching exercises to reduce central complications caused by poor posture, determine the preferred intervention and introduce it for workplaces.