Is reaction time altered by mental or physical exertion?

Relationship between Fear-Avoidance Beliefs and Reaction Time Changes Prior to and following Exercise-Induced Muscle Fatigue in Chronic Low Back Pain

Background

Reaction time is a reliable indicator of the velocity and efficiency of neuromuscular control and may be associated with fear-avoidance beliefs. However, the effect of exercise-induced muscle fatigue on reaction time in chronic low back pain (cLBP) and its relationship with fear-avoidance beliefs remains poorly understood.

Objectives

This study aimed to reveal the relationship between fear-avoidance beliefs and reaction time changes before and after exercise-induced muscle fatigue in cLBP.

Methods

Twenty-five patients with cLBP were tested by the Biering-Sorensen test (BST) to induce exhaustive muscle fatigue. Total reaction time (TRT), premotor time (PMT), and electromechanical delay (EMD) of dominated deltoid muscle were recorded by surface electromyography during the arm-raising task with visual cues before and after muscle fatigue. The mean difference (MD) of TRT (MDTRT), PMT (MDPMT), and EMD (MDEMD) was calculated from the changes before and after muscle fatigue. Fear-avoidance beliefs questionnaire (FABQ) was applied to evaluate fear-avoidance beliefs before muscle fatigue. In addition, the duration time of BST was recorded for each subject.

Results

TRT and PMT of dominated deltoid muscle were prolonged after exercise-induced muscle fatigue (Z = 3.511, p < 0.001; t = 3.431, p = 0.001), while there was no statistical difference in EMD (Z = 1.029, p = 0.304). Correlation analysis showed that both the MDTRT and MDPMT were positively correlated with FABQ (r = 0.418, p = 0.042; r = 0.422, p = 0.040).

Conclusions

These findings suggested that we should pay attention to both muscle fatigue-induced reaction time delay in cLBP management and the possible psychological mechanism involved in it. Furthermore, this study implied that FABQ-based psychotherapy might serve as a potential approach for cLBP treatment by improving reaction time delay. This trial is registered with ChiCTR2300074348.

The stroke rate influences performance, technique and core stability during rowing ergometer

The aim of this study is to determine the effect of stroke rate on performance, technique and core stability during rowing ergometer. Twenty-four high-level rowers performed maximal intensity one-minute bouts at 20, 28 and 34 spm on a RowPerfect3 ergometer. Power at the handle, legs, trunk and arms levels were determined, and core kinematics and neuromuscular activations were measured. The power at the handle was enhanced with a higher stroke rate in the first half of the drive phase due to higher segment's powers. This resulted in technical changes, as for instance greater mean to peak power ratio at each segment level. The higher trunk power preceded a delayed trunk extension but without significant increase in the erector spinae activation. This underlines the role of the core stability to transfer forces at a higher stroke rate. However, no co-activation parameters between trunk flexors and extensors helped further to understand this force transfer. Rowing at low stroke rate can be a training strategy to work on earlier trunk extension, while maintaining erectors spinae levels of activation. Training at higher stroke rate will induce a rowing technique closer to competition with greater neuromuscular activations, and maximise power production.

Optimizing Reaction Time in Relation to Manual and Foot Laterality in Children Using the Fitlight Technological Systems

The purpose of the study was to design and implement, in the physical and sports education process and in the motor evaluation process, a program of exercises and specific tests to optimize reaction time by using the Fitlight technological systems in relation to the manual and foot laterality of the pupils and identification of gender differences regarding the development of reaction speed. The study included 231 pupils, between 10 and 11 years old, who were divided into two groups according to gender, as follows: the male sample included 109 (97.32%) subjects, and the female sample included 103 (94.45%) participants. All subjects were identified with right manual and foot laterality. Both samples performed a specific exercise program to optimize reaction time in relation to manual and foot laterality by using Fitlight technologies. In the study, four tests were applied in order to evaluate reaction times using Fitlight, two in relation to the manual laterality and two with foot laterality, and the results were statistically processed with IBM SPPS Statistic 24 (IBM Corp., Armonk, NY, USA). Through the comparative analysis of the samples and the progress aimed at optimizing the reaction time specific to our study, it was found that the female sample recorded greater progress at the level of manual laterality, both for the right hand and for the left one, while the sample of boys recorded significant progress in terms of improving reaction time at the level of right and left foot laterality. At the foot laterality level, the results for the executions with the right foot were better in the simple test with four Fitlight spotlights in a line, and for the complex test, with eight Fitlight spotlights in a square, the results were better in the executions with the left foot. This reveals the fact that the greater the execution complexity, the better the motor prevalence on the left side.

Match Analysis, Physical Training, Risk of Injury and Rehabilitation in Padel: Overview of the Literature

Padel is a racket sport that has been gaining great popularity and scientific interest in recent years. It could be considered to be a high-intensity intermittent sport with valuable cardiovascular and neuromuscular benefits; however, the risk of injury cannot be neglected. To date, there is still a gap of knowledge in the scientific literature on this emergent sport. Therefore, the present review aims to synthetize the current knowledge on padel game dynamics to better characterize the main risk factors, the injury rate and characteristics, and the most effective rehabilitative treatment strategies. PubMed, Scopus, Cochrane, and PEDro were screened up to January 2022 to identify eligible studies focusing on padel players as participants. Out of 160 records, we included 19 studies, which were focused on match analysis, anthropometric and physical training, the risk of injury, and rehabilitative interventions. The results showed that the high action velocity and the sudden changes in direction during a padel match could represent a risk factor for injuries, especially in untrained players. However, the high heterogeneity of the studies in the literature hinders our ability to draw any strong conclusions, and the results should be carefully considered. Future research should address the lack of knowledge on injury mechanisms and type to implement a tailored rehabilitation program.

How Mentally Fatiguing Are Consecutive World Padel Tour Matches?

It is currently unknown whether mental fatigue occurs throughout a WPT competition and whether consecutive matches affect how mentally fatiguing a match is perceived to be. The objective was to quantify the effects of successive professional matches on mental fatigue. A total of 14 professional players (9 males, Mage = 25, 5 females, Mage = 21) participated during qualified rounds of a WPT with three eliminatory matches: Match 1 (morning) and 2 (afternoon) on day 1 (n = 14), Match 3 (morning) on day 2 (n = 6). Mental fatigue and motivation, with scales, and reaction time, with a 3-min Psychomotor Vigilance Test, were measured at two time intervals (pre and post matches (<30 min)). To analyze the evolution of these variables, a two-way repeated measures MANOVA was performed. An increase in mental fatigue from pre- to post-matches was observed (p < 0.01), with an accumulation of mental fatigue between matches played on day 1 (p < 0.01), maximizing the mental fatigue perceived during Match 2. Padel matches impair motivation and reaction time (p = 0.04), without effects between successive matches, which reinforced the idea that mental fatigue may impair padel performance (i.e., reaction time). Coaches should use training interventions and recovery strategies to counteract/avoid the accumulation of mental fatigue during professional tournaments.

Objective electrophysiological fatigability markers and their modulation through tDCS

OBJECTIVE

Cognitive fatigability is a frequent symptom after sustained performance. Fatigability is evident in healthy subjects but is also often comorbid in several neuropsychiatric diseases. However, to date, clinical diagnostic almost solely relies on the self-reported subjective experience of fatigue. The goals of this present study were i) to complement the purely subjective fatigue diagnostic with objective electrophysiological fatigability parameters and ii) to prove the potential therapeutic application of transcranial direct current stimulation (tDCS) as a fatigability intervention.

METHODS

We performed a pseudo-randomized, sham-controlled, parallel-group trial. Forty healthy participants received either anodal or sham tDCS over the left dorsolateral prefrontal cortex (DLPFC) while they performed an exhaustive cognitive task to induce cognitive fatigability. To assess fatigability changes, we analyzed variations of prepulse inhibition (PPI) and P50 suppression as well as frontomedial theta and occipital alpha power with time-on-task.

RESULTS

The task reliably induced subjective exhaustion in all participants. Furthermore, we confirmed fatigability-related increases in frontomedial theta and occipital alpha power throughout the task. Additionally, fatigability significantly reduced PPI as well as P50 sensory gating. Anodal tDCS over the left DLPFC successfully counteracted fatigability and reduced the fatigability-related increase in alpha power as well as the decline in both gating parameters.

CONCLUSION

Occipital alpha and sensorimotor/sensory gating are suitable parameters to assess the severity of fatigability objectively. Anodal tDCS can counteract fatigability and has therapeutic potential for the treatment of fatigability in neuropsychiatric diseases.

SIGNIFICANCE

Fatigability can be objectively assessed by electrophysiological measures and attenuated by tDCS.