Fatigue

Background and Purpose: Increasing participation in sports activities has increased the incidence of sports injuries. Considering the short and long term complications of sports injuries, the need to prevent them is one of the most important goals. The purpose of this study was to evaluate the effects of ankle bracing on the ankle plantar flexor muscles activity in different foot position during drop landing with and without fatigue. Method: Fourteen female college athletes participated in this study. Five models of 5 and 10 degrees medial, lateral and normal wedged insoles were used to simulate the position of the feet on the ground at the wrong landing technique. The Medial Gastrocnemius (MG) and Peroneus Longus (PL) muscles activity 100 ms before and 100ms after landing in different foot position before and after muscles fatigue with and without ankle bracing was recorded with surface electromyography. Repeated measures ANOVA was used for statistical analysis (p≤0.05). Results: The results showed that the effect of time on the activity of MG and PL muscles in landing with brace was significant, so that the MG muscle before landing and PL muscle after landing had a higher activity in both times before and after fatigue (p≤0.001). The activity of this muscles was not significant when using the ankle brace during landing in different positions (p˃0.05). Conclusions: According to the results of this study, lace-up brace can help to increase muscles activity when they were fatigue, while the using of brace does not affect muscle activity when landing perform in different positions without fatigue. According to the results, In the case of a suggestion to use brace for athletes, all aspects of using this equipment should be considered.

Introduction: Since people experience fatigue after anterior cruciate ligament injury during exercises, it is important to understand how fatigue affects the biomechanical movement patterns. Therefore, this study aimed to investigate the effect of fatigue on ground reaction force variables during single-leg landing in athletes with a history of an anterior cruciate ligament sprain. Methods: it was a case-control study conducted in the University Laboratory. The sample consisted of 36 male athletes who were divided into three groups: 12 people with Anterior Cruciate Ligament Reconstruction (ACLR), 12 people with Anterior Cruciate Ligament Deficiency (ACLD), and 12 people as the control group. Fatigue was induced via the repetitive sets of double-leg squats (n=8), which were interspersed with the sets of countermovement jumps (n=2) and single-leg landings (n=3) until squats were no longer possible. A 2×2 repeated-measures multivariate analysis of variance was used to detect the main effects of group (ACLD, ACLR, control) and fatigue state (prefatigue, postfatigue) on the ground reaction forces variables. Results: The results showed a significant decrease in the peak vertical force and internal-external ground reaction force in the ACLD group after fatigue. Regardless of the fatigue state, the peak vertical ground reaction force in ACLD and ACLR groups was significantly lower than that in the control group. Conclusion: The athletes with the ACL injury, regardless of the selective treatment type, use compensatory strategies to reduce the contact forces on the lower extremity, compared with healthy athletes.

Objective: Hemodialysis patients suffer many problems including feelings of loneliness, fatigue, and low lifestyle quality. This study aimed to investigate the effectiveness of online existential consciousness therapy on these patients’ loneliness, fatigue, and lifestyle. Methods: The research method was quasi-experimental with a pretest-posttest and follow-up design with a control group. The research population was all hemodialysis patients who were referred to the dialysis center of Nikan Hospital in Tehran. Using the convenience sampling method, 30 participants were selected as study samples. Research instruments for collecting data were the Rasel’s Loneliness Questionnaire (1978), the Fieck’s Fatigue Impact Questionnaire (1944), and the Corona Virus Lifestyle Scale (Ali Akbari Dehkordi, et al., 2020). For the experimental group, ten 90-minutes sessions were performed through Sky-room. Results: MANCOVA and ANCOVA showed that existential consciousness training reduced the feeling of loneliness in the sub-components of not having a close friend, lack of loneliness, and isolation, but was not effective in the sub-component of sociability. This intervention also reduced the fatigue in the cognitive and social components but did not affect the physical component. It was also effective on the happy lifestyle but did not affect on the healthy lifestyle. Conclusions: Existential consciousness therapy was effective in reducing the loneliness feeling, fatigue impact, and lifestyle changes of hemodialysis patients during home quarantine. Therefore, this method can be used as a new therapeutic approach to reduce the loneliness and fatigue impact caused by hemodialysis and change patients' lifestyles during quarantine in medical centers and psychological services.

Premenstrual syndrome is one of the commonest disorders among women with premenstrual period. The aim of the present study was to determine the relationship of anger and fatigue with family functions among women with premenstrual syndrome. The research sample consisted of 120 women who were selected among women with premenstrual syndrome in Ardabil, Iran. To collect the data, State-Trait Anger Expression Inventory-2, Fatigue Scale, Family Assessment Scale, and Daily Symptom Rating Form were used. The results showed that anger and fatigue are significantly related to family functions in women. The results of multiple regression showed that anger and fatigue explained 42 percent of variance family functions of women. Also results support the role of anger and fatigue on family functions. The results have important implications about prevention and counseling in women with premenstrual syndrome. The findings indicate that clinicians should use psychological trainings to cope with the consequences and symptoms of premenstrual syndrome.

The present research aims to investigate the effect of massage on fatigue and mood in female rowers. Pre-test and post-test of quasi-experimental design with a control group was used for the experiment. Participants in the study were 30 female rowers from Tehran province who participated voluntarily. The volunteer sample was randomly assigned into two experimental and control groups (15 people in each group). Pre-test was carried out for both groups. The subjects in the experimental group then participated in 12 massage sessions under the supervision of a massage expert. Meanwhile, both groups also continued their normal rowing exercises. At the end of the intervention, post-test was carried out for both groups. Rating of perceived exertion and fatigue scale (Borg, 1982), mood questionnaire (Vaez Mousavi, 2007), and a researcher-made questionnaire were used to measure variables. Statistical analysis of variance with repeated measurements was used to test the hypotheses. The results suggested that perceived intensity and fatigue were significantly reduced in the massage group compared to the control group (P <0.05). Also, anger (P=0.002), confusion (P=0.02), depression (P=0.028), mood fatigue (P=0.015), and stress (P=0.039) significantly decreased in the massage group compared to the control group. Force increased significantly in the massage group compared to the control group (P=0.008). In general, the results showed that 12 massage sessions could be used to decrease fatigue and improve mood in female rowers.

Introduction : Sleep deprivation is one of common phenomena in athletes. The aim of the present study was to investigate the influence of arginine supplementation following sleep deprivation on carbohydrate and fat metabolism, balance and fatigue index in female athletic students. Methods: The study population included all undergraduate female students of Sport Sciences at Imam Khomeini International University (age: 22.2± 2.16 years, BMI: 230.15±2.59 kg/m<sup>2 ) of whom 8 volunteered took part in the research. All experiments were performed in laboratory of university in 2020. Subjects were classified into four groups: Control, Sleep deprivation, Arginine and Arginine-sleep deprivation. Lactometer was used to measure blood lactate. Best Balance device was used to measure balance and GAS Analyzer was used to measure metabolism. Data was analyzed by analysis of covariance (ANCOVA). Results: Sleep deprivation significantly decreased static balance ( P =0.01) and dynamic balance ( P = 0.004) while arginine consumption resulted in improved static balance in sleep deprivation arginine group ( P =0.03). It was also shown that lactic acid levels were lower in the two groups that took arginine than in the groups that did not take arginine ( P ≤0.05). Conclusion: Arginine consumption can improve static and dynamic balance as well as mitigate side effects of sleep deprivation on static balance.

Background: Drop landing is one of the tasks performed in many sports skills. Lower limb injuries have the highest prevalence in sports where jump landing is repeated frequently. One of the most common landing injuries is an anterior cruciate ligament (ACL) tear, which increases knee valgus and may contribute to an increased risk of ACL injury in athletes. In this situation, fatigue is one of the components that can affect various parameters of the landing task. Aim: The purpose of this study was to investigate and compare the acute and delayed effects of fatigue on the time to stability (TTS) of female gymnasts with and without dynamic knee valgus (DKV) during the landing task. Materials and Methods: In this semi-experimental study with a pretest-posttest design, 42 female gymnasts were selected through purposive and available sampling and divided into two groups of 21: a control group without DKV and an experimental group with DKV. The TTS in these individuals was measured before, after, and 24 hours after the fatigue protocol using the Kistler force plate device. The data was analyzed using SPSS software and statistical methods of analysis of covariance with repeated measures at a significance level of P ≥0.05. Results: According to the findings of this study, it showed that there is a significant difference in the variable of TTS in three time periods (before, after, 24 hours after fatigue) in the control and experimental groups ( P = 0.026). Conclusion: The results of the present study showed that plyometrics on the TTS are significantly different between people with DKV and without DKV, and people with DKV are necessarily at a greater risk of injury during landing tasks.

Purpose: This study was conducted aiming to investigate the effect of selected TRX and Pilates training on balance parameters, fatigue index, and quality of life in female patients of multiple sclerosis. Method: In this study, 30 female patients with MS in Isfahan city with an average age of 37.41 ± 7.57 years and a history of MS of 11.31 ± 3.77 years and an Expanded Disability Status Scale of 0.84 ± 1.81 were placed in three groups including control, TRX and Pilates groups. The training program consisted of eight weeks including 3 sessions of 60 minutes of exercise per week. In order to investigate balance, fatigue, and quality of life, the Berg test, Fatigue Severity Scale, and Multiple Sclerosis Quality of Life were used respectively. SPSS version 25 software was used for statistical analysis. Results: The results of this study have shown that both exercise programs have led to a significant improvement in the mean parameters of balance (P < 0.005), fatigue (P < 0.005), and quality of life (P < 0.001). Conclusions: Considering the noticeable impact of these training protocols on the quality of life, balance and fatigue, these interventions can be considered as an efficient and cost-effective methods to improve health condition in MS patients.

The phenomena of fatigue of voluntary muscular effort is intricate and multidimensional in the field of sports sciences. The causes and effects of exercise-induced fatigue have been extensively studied, but the central nervous system's (CNS) involvement in this process is still unclear. In order to understand CNS fatigue after physical activity, the current review will examine changes in neurotransmitter function during exercise. Using primary sources such scientific journals and websites, a consensus and critical evaluation were carried out in order to accomplish this goal. For a number of neurotransmitters, including dopamine and serotonin (5-HT; 5-hydroxytryptamine), hypotheses have been established. The most well-known one is a rise in serotonin levels throughout the brain. Nutritional interventions intended to reduce brain serotonin synthesis during extended exercise enhance endurance performance, and there is strong evidence that increases and decreases in brain serotonin activity during prolonged exercise, respectively, accelerate and delay fatigue. There are several physiologically connected causes of fatigue. It is important to better understand how CNS effects affect fatigue in order to achieve maximum muscle performance in both daily life and athletics.

Background: Fatigue as one of the physiological factors can affect the physical performance of athletes. This issue is more important in young athletes and can expose them to injury. Aim: The purpose of this research was to investigate the effect of functional fatigue on the performance and landing mechanics of adolescence taekwondo athletes. Materials and Methods: This was a semi-experimental study. Participants were 20 male teenage taekwondo players. Pre-fatigue measurements included side-jump tests, figure-8 hop tests, and single-leg triple jump tests, as well as a lower limb biomechanics assessment using a landing error scoring system. After the functional fatigue protocol was applied, all the pre-fatigue variables were evaluated again. In order to examine the intra-group changes of the research variables in the pre and post-test stages, the paired t-test at a significance level of P≤0.05 was used. Results: The paired-t test results revealed that following fatigue induction, performance in the side-jump and figure-8 hop tests significantly deteriorated (P<0.05). Additionally, performance in the single-leg triple hop test declined (P<0.05). Moreover, landing error significantly increased (P<0.05). Conclusion: The finding of this study indicated that after applying fatigue, the subjects' performance decreased and the biomechanical error of the lower limbs increased. Fatigue can significantly impact adolescent taekwondo athletes' performance and biomechanics. So, taekwondo coaches should implement effective strategies to mitigate fatigue, enhance athletes' conditioning, and optimize their performance in training and competitions.