scholarly journals Effects of Melatonin on Neurological Function and Maintenance of Physical and Motor Fitness in Collegiate Student-Athletes Following Sleep Deprivation

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Nesa Paryab ◽  
Morteza Taheri ◽  
Kahdijeh Irandoust ◽  
Masoud Mirmoezzi
Keyword(s):  
Reaction Time ◽  
Sleep Deprivation ◽  
Repeated Measures ◽  
Student Athletes ◽  
Anaerobic Power ◽  
Neurological Function ◽  
Placebo Control ◽  
Motor Fitness ◽  
Significant Difference ◽  
Training Protocols

Background: Melatonin is one of the Supplements used to treat sleep problems such as insomnia and jet lag. Objectives: Since sleep deprivation may affect athletic performance, the aim of this study was to investigate the effect of melatonin on neurological function and maintenance of physical and motor fitness in collegiate student-athletes following sleep deprivation. Methods: Ten collegiate student-athletes participated in randomized, double‐blind crossover trial with placebo control. Subjects were divided into six experimental groups: without sleep deprivation (WSD), 4 hours sleep deprivation (4HSD) and 24 hours sleep deprivation (24HSD) with melatonin (MEL) or placebo (PLA). WSD were allowed to sleep eight hours per night. Six milligrams of melatonin was administered 30 min before the training protocols. Training protocols included the Wingate Anaerobic test, Good Balance test, Vienna reaction time with the Stroop test. Data were analyzed using repeated measures ANOVA. Significant difference was set at P ≤ 0.05. Results: Six mg/day of MEL 30 min before training had no significant effect on anaerobic power, balance and reaction time in collegiate student-athletes WSD (P > 0.05). Although, 4HSD and 24HSD negatively affected balance function, MEL reduced its negative effects. Furthermore, 24HSD decrease neurological and physical performance in collegiate student-athletes and MEL improved anaerobic power and reaction time in collegiate student-athletes (P < 0.05). Conclusions: Pre-training MEL supplementation would alleviate neurological, physical and motor performance impairment in collegiate student-athletes following sleep deprivation. MEL appears to be more effective in athletes with longer sleep deprivation.

scholarly journals Driver Take-Over Reaction in Autonomous Vehicles with Rotatable Seats

Safety ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 34
Author(s):  
Shi Cao ◽  
Pinyan Tang ◽  
Xu Sun
Keyword(s):  
Reaction Time ◽  
Interior Design ◽  
Situation Awareness ◽  
Repeated Measures ◽  
Autonomous Vehicles ◽  
Driving Simulator ◽  
Autonomous Driving ◽  
Maximum Magnitude ◽  
Significant Difference ◽  
Driving Conditions

A new concept in the interior design of autonomous vehicles is rotatable or swivelling seats that allow people sitting in the front row to rotate their seats and face backwards. In the current study, we used a take-over request task conducted in a fixed-based driving simulator to compare two conditions, driver front-facing and rear-facing. Thirty-six adult drivers participated in the experiment using a within-subject design with take-over time budget varied. Take-over reaction time, remaining action time, crash, situation awareness and trust in automation were measured. Repeated measures ANOVA and Generalized Linear Mixed Model were conducted to analyze the results. The results showed that the rear-facing configuration led to longer take-over reaction time (on average 1.56 s longer than front-facing, p < 0.001), but it caused drivers to intervene faster after they turned back their seat in comparison to the traditional front-facing configuration. Situation awareness in both front-facing and rear-facing autonomous driving conditions were significantly lower (p < 0.001) than the manual driving condition, but there was no significant difference between the two autonomous driving conditions (p = 1.000). There was no significant difference of automation trust between front-facing and rear-facing conditions (p = 0.166). The current study showed that in a fixed-based simulator representing a conditionally autonomous car, when using the rear-facing driver seat configuration (where participants rotated the seat by themselves), participants had longer take-over reaction time overall due to physical turning, but they intervened faster after they turned back their seat for take-over response in comparison to the traditional front-facing seat configuration. This behavioral change might be at the cost of reduced take-over response quality. Crash rate was not significantly different in the current laboratory study (overall the average rate of crash was 11%). A limitation of the current study is that the driving simulator does not support other measures of take-over request (TOR) quality such as minimal time to collision and maximum magnitude of acceleration. Based on the current study, future studies are needed to further examine the effect of rotatable seat configurations with more detailed analysis of both TOR speed and quality measures as well as in real world driving conditions for better understanding of their safety implications.

Comparing the Effects of Peroneal Muscle Fatigue and Cyclic Loading on Ankle Neuromuscular Control During Lateral-Hop Landing

2015 ◽  
Vol 24 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Kazem Malmir ◽  
Gholam Reza Olyaei ◽  
Saeed Talebian ◽  
Ali Ashraf Jamshidi
Keyword(s):  
Reaction Time ◽  
Muscle Fatigue ◽  
Energy Absorption ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Neuromuscular Control ◽  
Median Frequency ◽  
Peroneus Longus ◽  
Significant Difference ◽  
Main Effect

Context:Cyclic movements and muscle fatigue may result in musculoskeletal injuries by inducing changes in neuromuscular control. Ankle frontal-plane neuromuscular control has rarely been studied in spite of its importance.Objective:To compare the effects of peroneal muscle fatigue and a cyclic passive-inversion (CPI) protocol on ankle neuromuscular control during a lateral hop.Design:Quasi-experimental, repeated measures.Setting:University laboratory.Participants:22 recreationally active, healthy men with no history of ankle sprain or giving way.Interventions:Participants performed a lateral hop before and after 2 interventions on a Biodex dynamometer. They were randomly assigned to intervention order and interventions were 1 wk apart. A passive intervention included 40 CPIs at 5°/s through 80% of maximum range of motion, and a fatigue intervention involved an isometric eversion at 40% of the maximal voluntary isometric contraction until the torque decreased to 50% of its initial value.Main Outcome Measures:Median frequency of the peroneus longus during the fatigue protocol, energy absorption by the viscoelastic tissues during the CPI protocol, and feedforward onset and reaction time of the peroneus longus during landing.Results:A significant fall in median frequency (P < .05) and a significant decrease in energy absorption (P < .05) confirmed fatigue and a change in viscoelastic behavior, respectively. There was a significant main effect of condition on feedforward onset and reaction time (P < .05). No significant main effect of intervention or intervention × condition interaction was noted (P > .05). There was a significant difference between pre- and postintervention measures (P < .0125), but no significant difference was found between postintervention measures (P > .0125).Conclusions:Both fatigue and the CPI may similarly impair ankle neuromuscular control. Thus, in prolonged sports competitions and exercises, the ankle may be injured due to either fatigue or changes in the biomechanical properties of the viscoelastic tissues.

scholarly journals Muscular Strength and Hydroxyproline Concentration in Urine After Different Flexibility Training Protocols

2010 ◽  
Vol 29 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Olavo de Almeida ◽  
Adriane de Oliveira Sampaio ◽  
Mário Conceição ◽  
Vivian Paranhos ◽  
Danielli Mello ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Muscular Strength ◽  
Sample Population ◽  
Fat Percentage ◽  
Significance Level ◽  
Hydroxyproline Concentration ◽  
Significant Difference ◽  
Flexibility Training ◽  
Increased Strength ◽  
Training Protocols

Muscular Strength and Hydroxyproline Concentration in Urine After Different Flexibility Training ProtocolsThe objective of this study was to evaluate variation in the lumbar spine extension (LSE) muscular strength index and the hydroxyproline (HP) urinary concentrations as a function of flexibility training with maximum intensity (flexibilizing) statically, by proprioceptive neuromuscular facilitation (PNF) and submaximally. The sample population - with an age of 17.13 ± 1.23; body mass of 63.23 ± 6.36 kg; height of 173.62 ± 5.465 cm and body fat percentage of 10 ± 3.62% - comprised 60 male individuals divided randomly into four equal groups: CG (control), StrG (stretching), SFG (static flexibilizing) and PNFG (flexibilizing by PNF). The statistical program SPSS 14.0 for Windows was used to perform a Shapiro Wilk test to verify the normality of the data and Levene's test to analyze the homogeneity of the sample, repeated measures ANOVA for multiple comparisons among groups and the Tukey's HSD Post Hoc test to determine the statistical difference within groups of the variables. A significance level of 95% (p<0.05) was adopted. The results showed a significant difference in LSE between PNFG and CG (D% = 11%; p = 0.029). It can be concluded that the practice of PNF increased strength in the study group.

scholarly journals Acute effects of different stretching and warm up protocols on some anaerobic motoric tests, flexibility and balance in junior male judokas

2020 ◽  
Vol 24 (4) ◽  
pp. 169-174
Author(s):  
Özgür Eken ◽  
Mehmet Z. Özkol ◽  
Saadet R. Varol
Keyword(s):  
Repeated Measures ◽  
Vertical Jump ◽  
Anaerobic Power ◽  
Static Stretching ◽  
Acute Effects ◽  
Strength Performance ◽  
Warm Up ◽  
Leg Strength ◽  
Significant Difference ◽  
Strength Improvement

Background and Study Aim: The aim of this study is to investigate acute effects of different warm-up and stretching protocols, on 30 m. sprint, flexibility, vertical jump, strength, balance and anaerobic power performances in junior male judokas. Material and Methods: Twenty sub-elite 11-14 year old judokas who volunteered to participate in the study (age: 12,25±0,96 years; height: 1,52±0,11cm; body mass: 48,06±14,22 kg). This study consist of four different stretching and warm up protocols; without stretching (WS); static stretching (SS); dynamic warm up (DW); dynamic+static warm up (DSW). Results: The effect of the four stretching and warm up protocols were analysed by an ANOVA for repeated measures (WS x SS x DW x DSW). After stretching and warm up protocols, 30 m. sprint values are statistically significance (p<0.05). There was find statistically significant between WS and DSW, SS and DW, DW and DSW (p<0.05). There were no significant difference is found on flexibility values between four stretching and warm up protocols (p>0.05). There was only significant difference is found between WS and SS (p<0.05). Altough leg strength performance wasn’t statistically significant (p>0.05), there was found significant differences between WS and DSW, SS and DSW in favour of DSW (p<0.05). Other parameters like vertical jump, balance and back strength performance weren’t statistically significant after four stretching and warm up protocols. Conclusions: Consequently it is suggested for coaches and judokas that SS are required for developing flexibility performance and DSW can suggest for leg strength improvement.

scholarly journals Concussion in Sports: Postconcussive Activity Levels, Symptoms, and Neurocognitive Performance

2008 ◽  
Vol 43 (3) ◽  
pp. 265-274 ◽  
Author(s):  
Cynthia W. Majerske ◽  
Jason P. Mihalik ◽  
Dianxu Ren ◽  
Michael W. Collins ◽  
Cara Camiolo Reddy ◽  
...  
Keyword(s):  
Reaction Time ◽  
Verbal Memory ◽  
Repeated Measures ◽  
Visual Memory ◽  
Student Athletes ◽  
Activity Level ◽  
Activity Levels ◽  
Motor Speed ◽  
Neurocognitive Performance ◽  
Activity Intensity

Abstract Context: Evidence suggests that athletes engaging in high-intensity activities after concussion have more difficulties with cognitive recovery. Objective: To examine the role postinjury activity level plays in postconcussive symptoms and performance on neurocognitive tests in a population of student-athletes. Design: Retrospective cohort study with repeated measures of neurocognitive performance and symptom reporting. Setting: University-based sports concussion clinic. Patients or Other Participants: Ninety-five student-athletes (80 males, 15 females: age  =  15.88 ± 1.35 years) were retrospectively assigned to 1 of 5 groups based on a postinjury activity intensity scale. Main Outcome Measure(s): We employed a regression analysis for repeated measures to evaluate the relationship of activity intensity to symptoms and neurocognitive outcome up to 33 days after concussion. Postconcussion symptom scores and neurocognitive (verbal memory, visual memory, visual motor speed, and reaction time) scores served as the primary outcome measures. Results: Level of exertion was significantly related to all outcome variables (P &lt; .02 for all comparisons). With multivariate analysis, activity intensity remained significant with respect to visual memory (P  =  .003) and reaction time (P &lt; .001). Conclusions: Activity level after concussion affected symptoms and neurocognitive recovery. Athletes engaging in high levels of activity after concussion demonstrated worse neurocognitive performance. For these tasks, those engaging in moderate levels of activity demonstrated the best performance.

Investigating the Effect of Cognitive-behavioral Stress Management on Occupational Performance among Women with Breast Cancer

2020 ◽  
Vol 16 (2) ◽  
pp. 152-159
Author(s):  
Arezoo Shayan ◽  
Mansoureh Refaei ◽  
Farkhondeh Jamshidi
Keyword(s):  
Breast Cancer ◽  
Stress Management ◽  
Repeated Measures ◽  
Intervention Group ◽  
Performance Measure ◽  
Cognitive Behavioral ◽  
Occupational Performance ◽  
Cognitive Behavioral Stress Management ◽  
Behavioral Stress ◽  
Significant Difference

Background: Treatment of breast cancer can be accompanied by long-term consequences affecting women’s participation in many tasks. Objective: This study aimed to assess the effect of cognitive behavioral stress management (CBSM) program on occupational performance of women with breast cancer. Methods: In this randomized clinical trial, conducted between Feb 3 and Oct 26, 2016, 104 women with breast cancer who had referred to Imam Khomeini clinic in Hamadan, and who fulfilled the inclusion criteria (20-60 years old, married, suffering from grade 1-3 breast cancer with a history of recent surgery) were enrolled. They were randomly divided into two groups of 52 using a permuted block size of four. The intervention group took part in four 60-minute sessions of CBSM over four weeks. The study data were collected using a demographic information form and the Canadian Occupational Performance Measure. The statistical analyst was masked to intervention allocation. The data were analyzed using descriptive statistics, paired t-test, and repeated measures ANOVA. Results: A significant difference was observed between the two groups regarding the mean scores of occupational performance (p=0.02) and satisfaction (p=0.005) after the intervention. Each variable was measured at three time points (before the intervention, immediately and 2 weeks after intervention). A significant difference was observed in the two groups’ mean scores of performance (p=0.026) and satisfaction (p=0.01), irrespective of the time of assessment. Conclusion: The CBSM program promoted the occupational performance immediately and two weeks after the intervention in women with breast cancer. This technique can be used as a complementary method alongside medical therapies in oncology centers.

scholarly journals Cytotoxicity assessment of different doses of ozonated water on dental pulp cells

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ferdiye Küçük ◽  
Sibel Yıldırım ◽  
Serap Çetiner
Keyword(s):  
Cell Viability ◽  
Repeated Measures ◽  
Dental Pulp ◽  
Control Group ◽  
Dental Pulp Cells ◽  
Time Points ◽  
Significant Difference ◽  
Pulp Cells ◽  
Time Point ◽  
Ozonated Water

Abstract Background The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells. Methods Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann’s Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons. Results All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn’t experience any statistically significant difference (p < 0.05). Conclusion Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.

Sign in / Sign up

Export Citation Format

Share Document