Showing 15 results for Fatigue
Mrs Masume Fadaei, Dr Mehrdad Anbarian,
Volume 0, Issue 0 (11-2019)
Abstract
The purpose of this study was to evaluate the effect of quadriceps muscle fatigue on electromyographic activity of selected lower limb muscles during lifting loads using different techniques. Surface electromyography activity of the rectus femoris, vastus latralis, vastus medialis, biceps femoris, semitendinous, gastrocnemius medialis and tibialis anterior muscles of 20 able-bodied women were recorded before and after the quadriceps muscle fatigue using leg-press movement, squat, stoop and strudel techniques with 20% of body weight. Analysis of Variance with repeated measures was used for data analyses (p<0.05). After fatigue when lifting the load, the activity of the rectus femoris, vastus medialis, biceps femoris and gastrocnemius medialis in squat and stoop techniques was significantly different compared to before fatigue condition. But no significant difference was observed between the activity of any of the muscles before and after fatigue in the straddle method. According to the results, it seems that when quadriceps muscle fatigue, the use of straddle technique to lift the load is more appropriate.
Behnam Moradi, Amir Letafatkar, Malihe Hadadnezhad, Mehdi Hosseinzadeh, Mehdi Khalegi,
Volume 0, Issue 0 (11-2019)
Abstract
Introduction and aim: Fatigue of injury-prone athletes and their placement in situations such as performing shear maneuvers increases the risk of anterior cruciate ligament injury. Therefore, this research aims to answer the question, does functional fatigue change the effect of neuromuscular training on kinetic variables during cutting in injury-prone male athletes?
Methodology: The current research is semi-experimental and was carried out in two control and experimental groups as a pre-test and post-test design with and without fatigue before and after neuromuscular exercises. 32 males student-athletes aged 18 to 25 with trunk control defects were purposefully selected and randomly placed in the control group (16 people) and the experimental group (16 people). The force plane was used to measure ground reaction forces. Analysis of variance test was used for statistical analysis at a level smaller than P<0.05.
Results: The results of the present study showed a significant improvement in ground reaction force variables in the post-test of the experimental group compared to the pre-test (P<0.05). While none of these variables had significant changes in the control group (P>0.05).
Conclusion: It seems that doing trunk and hip neuromuscular training in athletes with a trunk control defect leads to a significant improvement in the stability of the trunk control, so in the conditions with and without fatigue, they were able to show a significant improvement in the selected parameters of the ground reaction forces. Therefore, this training method can probably be recommended as a beneficial method for athletes and the mentioned conditions
, , ,
Volume 0, Issue 0 (11-2019)
Abstract
Introduction: Balance and proprioception have been introduced as two of the most important internal factors related to the occurrence of injuries in the lower limbs. The purpose of this research is to investigate the changes in static and dynamic balance and proprioceptive accuracy of knee and ankle joints of young taekwondo athletes before and after applying the fatigue protocol.
Methodology: The current research is semi-experimental. The subjects of the research were 20 teenage male taekwondo players from the statistical population. Static and dynamic balance variables were measured respectively by Stork's static balance test and Y dynamic balance test, as well as the proprioception of the ankle and knee joints at 10 degrees of ankle dorsiflexion and 30 degrees of knee flexion, by the photographic method. Then the functional fatigue protocol was applied. After finishing the fatigue protocol, all the variables that were measured before applying the fatigue protocol 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 was used.
Results: The results of the paired t-test showed that after applying the fatigue protocol, there is a significant difference between the average of all the investigated variables in the post-test stage compared to the pre-test.
Conclusion: The results of the present research showed that fatigue can reduce the static and dynamic balance as well as the proprioceptive accuracy of teenage taekwondo athletes. Therefore, it is recommended to all coaches and athletes of this sport, in order to delay the appearance of fatigue and the possibility of injury, to perform specialized training exercises in the field of taekwondo and according to the age of teenagers.
, , ,
Volume 0, Issue 0 (11-2019)
Abstract
Background: Despite the relation between nervous system function, fatigue, and co-contraction, it seems that the difference in co-contraction changes due to fatigue induced by sprinting and endurance running probably indicates the dominance of one source of fatigue (central/peripheral) over the other. This study aimed to compare the effect of fatigue induced by endurance running and sprinting on the knee muscle co-contraction in active young women with the approach of identifying the origin of fatigue.
Methodology: Thirteen active young women volunteers (20-30 years, BMI 20-25kg/m2) were randomly selected. Subjects performed fatigue protocols during two sessions with four days of rest in between. The electrical activity of the vastus-medialis and vastus-lateralis muscles was recorded using an electromyography device before and after two stages of running 400-meter (with 100% effort) and 3000-meter (with 50% effort) during the execution of knee extension movement and co-contraction was calculated with the formula. Two-way repeated measure was used to analyze the data.
Results: There was no significant difference between the co-contraction of the selected muscles before and after sprinting (p=0.3) and endurance running (p=0.19) and no significant difference (p=0.85) between the difference in co-contraction rate in the pre-test and post-test of sprinting and endurance running.
Conclusion: Since there was no difference between the effect of fatigue caused by sprinting and endurance running on the co-contraction of the selected muscles, likely, the involvement of central factors in the appearance of fatigue caused by 400-meter sprinting and 3000-meter endurance running is similar and insignificant. The emergence of fatigue after the implementation of both protocols may be more due to environmental factors.
, , ,
Volume 9, Issue 2 (10-2011)
Abstract
The purpose of this study was to examine the effect of knee extensor and ankle
plantar flexor fatigue on dynamic balance among active elderly males. Fifteen
healthy individuals having age of 72±6.57 years, height of 168.4±4.8 cm and
weight of 70.5±7.4 kg without history of injuries at lower extremity, participated
in this study. Knee extensor and ankle plantar flexor muscles fatigued with free
sets of fifty repeated of knee extension and ankle plantar flexion loading with
50% of one repetition maximum (1RM), while four minutes rest applied between
every set. Fatigue protocol applied for each muscle group after 72 hours rest at
same environment condition. Star excursion balance test (SEBT) used to
measure dynamic balance before and after applying fatigue protocol.
Dependent and independent t-test used for data analysis in significant level
0.05. Significant differences shown between pre and post reaching distance
using SEBT. The results also showed significant differences between decrease
of reaching distance in SEBT after applying muscle fatigue protocols in knee
extensor and ankle plantar flexor. Due to results, increasing lower limb muscle
endurance, especially at knee, recommended for training program designitation
for elderly subjects to achieve dynamic balance improvement.
,
Volume 12, Issue 8 (10-2014)
Abstract
The aim of this study was to investigate the effect of functional fatigue on the dynamic and static balance of male students aged 15 to 18 with different plantar arch. To measure the subjects' foot arch, the Navicular Drop Test was used. The subjects were then randomly divided into three groups of 22 members with different foot arches. Later on, SEBT test, Modified Stork Balance, Fatigue Protocol and Borg (RPE) scale were run. Using SPSS (version 18), the data were analyzed (p< .05); in particular, dependent t-tests, One-way ANOVA and Scheffe's post hoc test were run. The results showed a significant difference between pre-test and post-test scores of dynamic and static balance in all three groups. Scheffe's post hoc test revealed that there was a significant difference between the mean difference of pre-test and post-test scores of the dynamic and static balance group of normal foot arch, the flat foot arch group and the cavus foot arch group. Meanwhile, the difference between flat and cavus foot group was not statistically significant. Due to the significant reduction in the balance of subjects with abnormal arch, the correction of the abnormality of the foot arch as well as the use of appropriate training courses are recommended to improve their physical fitness.
Seyed Hossein Mirkarimpour, Mohammad Falah Mohamaddi, Dr Mohammad Hossein Alizadeh,
Volume 13, Issue 9 (4-2015)
Abstract
One of the factors affecting jump-landing patterns is fatigue. Fatigue is an inevitable component of physical
activity, hence the aim of the present study was to investigate the effect of functional fatigue on landing
mechanics through Landing Error Scoring System (LESS).Fourteen male college students with a mean age of
22±2 years, weight of 68.3±7.2 kg and height of 174±4 were randomly divided into two groups: experimental and
control. Effect of independent variable, fatigue, due to activities resembling athletic training or competition (6-
stations functional fatigue protocol) on dependent variable, landing mechanics, through pre test-post test was
investigated. The independent t-tests and non-parametric U-Mann Whitney test was used for statistical analysis
of data (P < 0.05). The results of the present study indicated the relationship between fatigue and attenuation of
landing mechanics (P=0.02), and therefore an increase in injury risk. Also it was shown that the effect of fatigue
on decreasing knee flexion angle at initial contact was significant (P=0.022). With regard to the results, it can be
concluded that functional fatigue induced by physical activities can alter landing mechanics, and increase loading
of lower extremity joints, particularly the knee. So the risk of injury in these joints may be increased.
Masomeh Abdi, Hamed Esmaeili, Dr Farzad Nazem, Dr Mehrdad Anbariyan,
Volume 13, Issue 9 (4-2015)
Abstract
The aim of this study was to compare the effects of two pedaling methods on lower limb muscles fatigue
index and muscular activity in road cyclists. For this purpose eight road cyclists participated in two separately
session in laboratory. They were pedaling with pushing technique in first session and circling (pullingpushing)
technique in the other session. Surface electromyography activity of the Rectus Femoris, Vastus
Medialis, Vastus Lateralis, Biceps Femoris, Semitendinosous, Gastrocnemius Medialis, Gastrocnemius
Lateralis and Tibialis Anterior muscles of the subjects were recorded. Each session was performed
according to predetermined protocol until exhaustion. There was a significant difference between pushing
and rest phases during two pedaling techniques with higher muscle activity in pushing technique. Subjects
during circling technique exhausted later. According to the results of this study, the circling technique caused
lower muscle activity consequently, increases gross efficiency. It is recommended that road cyclists utilize
the circling technique.
Mr Saeid Eimani Zadeh, Dr Mansoor Sahebzamani, Dr Mohamad Taghi Amiri Khorasani,
Volume 13, Issue 10 (10-2015)
Abstract
The purpose of this study was to investigate the effect of soccer specific functional fatigue on hip and knee
joints angles during landing in professional players.15 soccer players with at least 2 years experience in
Kerman soccer clubs were selected randomly. To evaluate the lower extremity kinematics following
jumping and soccer specific- heading, three cameras (with50Hz) were used. To cause fatigue in subjects,
specific functional protocol similar to specific bangsbo soccer was used and Quantic sport v21 soft ware
was administrated for kinematic analysis of the recorded films. To statistical analyzing of data, descriptive
statistical methods, and paired-t test were administrated at α=0.05.Finding revealed that hip and knee
angles in sagittal and frontal plane in landing is influenced by functional fatigue. This results has been
reducing knee and hip flexion angles and increased varus in knee joint. Results demonstrated a more
erect landing posture due to a decrease in hip and knee flexion angles in the post fatigue condition.
However, functional fatigue significantly decrease lower extremity control ability in male soccer player
during landing.
Mansour Eslami, Mohsen Nazari,
Volume 16, Issue 15 (9-2018)
Abstract
All sustained physical activities subject the body to various levels of fatigue. This is especially evident when running, which is one of the most popular forms of exercise and may be described as a reduction in maximum force production and power output . the purpose of this study was to investigate the effect of running in an exerted state on knee muscles power absorption and work during the stance phase of running. Sixteen healthy physical education male students with an average age 22 and SD 2.27 years and height 177 and SD 5.47 cm and mass 72.6 and SD 8.4 kg participated in this study voluntary. Kinetic and kinematic data recorded by using of video camera and force plate. The negative and positive power and work of muscles operating on knee has calculated using inverse dynamic equations in MATLAB2010 Software. Paired sample T test was done to statistical analysis in SPSS 2010 software (p≤0.05). The results of this study indicated that negative peak power and work significantly decreased 33.78% and 22.6% respectively. Although the positive peak power significantly decreased (p≤0.05), positive work didn’t change significantly (p=0.644). The results of this research indicated that the absorbing function of the muscles is decreased following fatigue and may be led to increase the injury risk of running.
Amir Milan Amini, Mohamad Fashi, Rana Fayaz Milani,
Volume 18, Issue 20 (11-2020)
Abstract
This study aimed to assess the effects of acute calcium lactate supplementation intake on the performance and buffering capacity of elite amateur boxing athletes. 8 elite amateur boxers (180±4.33 cm, 24.12±3.68 years, Weight categories: -75, -64, -69, +81) were assigned to acutely receive calcium lactate (0.5 g, 80 mg calcium lactate/kg body weight) and placebo in a double-blind crossover design 90 minutes before the box competition. 90 minutes before, before competition and immediately after, blood samples were taken and lactate, PH, HCO3-, and PCO2 and also, average heart rate, and number of effective hand kick were evaluated. lactate and HCO3- significantly increased and decreased at three evaluation times in calcium lactate supplementation and placebo groups respectively (P<0.05). There was no significant difference between calcium lactate supplementation and placebo groups in lactate, pH, HCO3-, PCO2, heart rate and performance at three evaluation times (P>0.05) .Calcium lactate supplementation improves performance without significant changes in the buffering system. In other words, more effort with a similar acidity to placebo could indicate the effect of calcium lactate supplementation on the performance of amateur boxing athletes.
Dr. Leila Ghazaleh, Mis Fahimeh Bakhshizadeh, Dr. Rana Fayazmilani,
Volume 19, Issue 21 (9-2021)
Abstract
It is necessary to examine the changes of muscle co-contraction in different percent of fatigue-induced force reduction. The present study aims to investigate the effect of fatigue-induced force reduction of knee extension on muscle co-contraction. Ten healthy and active women aged 26.10±2.99 years performed fatigue protocol including 5 seconds of maximal voluntary isometric contraction (MVIC) of the knee extension and a 5-second rest. Muscle co-contraction was calculated for each subject in the repetitions in which the MVIC force was reduced by 10, 20, 30, 40 and 50% as compared to the pre-fatigue MVIC force. Knee extension force and muscle activity measured by Isokinetic and electromyography apparatus, respectively. The difference between co-contraction of vastus lateralis and medialis in different percentages of force reduction was not statistically significant. The co-contraction of rectus femoris and biceps femoris increased by 40 and 50% of force reduction compared to pre-fatigue co-contraction (P<0.01). Co-contraction of biceps femoris and vastus lateralis increased by 20, 30, and 40%, as well as co-contraction of biceps femoris and vastus medialis increased 40% of the force reduction, compared to pre-fatigue co-contraction (P <0.05). The results, overall, showed that the change of co-contraction during fatigue is influenced by the selected muscle and the rate of force reduction. This finding can help researchers decide how neuromuscular fatigue effects on muscle co-contraction
Ms Faezeh Gholami, Dr Manouchehr Haydari,
Volume 21, Issue 25 (9-2023)
Abstract
Mental fatigue is usually caused by long-term cognitive activities; in a way that reduces cognitive performance and leads to changes in functional activities. Therefore, the purpose of this study was to investigate the effect of a session of Swedish relaxation massage and meditation in controlling mental fatigue on reactive balance and Lower extremity function of amateur athletes. In this study, 16 female physical education athletes were purposefully selected as a sample based on the study entry criteria, and were subjected to mental fatigue protocol (45 minutes of cognitive activity (Stroop test)), Swedish relaxation massage (30 minutes) and meditation (30 minutes) with a time interval of 48 hours. Reactive balance was evaluated with Y test with automatic lights and, Lower extremity function was evaluated with single hop for distance, triple hop for distance, meter-6 and hop crossover-triple distance tests. Repeated analysis of variance test was used to check intra-group changes.The findings showed that there is a significant difference between the average scores of reactive balance and lower limb performance of the subjects when comparing the post-test of mental fatigue with the post-test of massage and meditation (P<0.05). Also, there is a significant difference between the subjects' scores comparing massage and meditation for reactive balance and body function (P<0.05).In order to prevent sports injuries in athletes, Swedish relaxation massage and meditation can be used as an intervention to speed up the recovery of mental fatigue and improve reactive balance and body function.
Hamidreza Barzegarpoor, Hamid Rajabi, Saied Mohammadi, Rana Fayazmilani,
Volume 22, Issue 27 (8-2024)
Abstract
Performing a mental exertion before and during an exercise increase fatigue indices. One of the important factors in inducing fatigue indices is the type of mental effort engaged. So, the purpose of the present study is comparing the effects of performing types of mental exertion during cycling exercise on fatigue indicators. Methods: 10 cyclist men (with average age 34.5 ± 4.5 kg, height 177 ± 4.5cm, peak power output 236 ± 36 W) invited for 5 different sessions. In the first session, anthropometric characteristics and of cycling peak power output have determined. In the next four sessions, cycling for 45-min at 65% PPO on the cycle ergometer with (Stroop, AX-CPT and PVT) or without (watching a movie) mental exertion. Rate of perceived exertion and heart rate were recorded while cycling every 10 min and cortisol concentration was measured before and 30 min after exercise finished. Two-way repeated-measures ANOVAs were used to analyzing data. Results: Performing 45 minutes of Stroop mental exertion during cycling exercise increased effort perception, mental demand in the NASA questionnaire, and cortisol concentration compared to cycling exercise alone (P˂0/05) but there is no differences between AX-CPT and PVT to cycling exercise alone . Conclusion: The results of present study showed that performing different mental effort simultaneously with the cycling exercise depending on the amount of challenge and their duration may affect some of the fatigue indices.
Elmira Ahmadi, Shahnaz Shahrbanian, Mohamadreza Kordi, Reza Gharakhanlou, Gregory Pearcey,
Volume 22, Issue 27 (8-2024)
Abstract
Fatigue is one of the most common symptoms among individuals with multiple sclerosis (MS). The imbalance of inflammatory cytokines in the brain causes mental fatigue. It is believed that aerobic exercise may moderate the level of inflammation of cytokines and thus reduce mental fatigue. This study was conducted to investigate the effect of swimming aerobic training on pro-inflammatory factors (interleukin 6) and anti-inflammatory factors (interleukin 10) to evaluate mental fatigue in the brains of female mice after EAE induction. In this research, 21 mice (8 weeks old, 18 to 20 grams) were divided into three groups: healthy control, EAE control, and EAE swimming aerobic exercise. The animals in the training group performed moderate-intensity swimming exercises for 4 weeks, with 5 sessions per week, each session lasting 30 minutes. The western blot method was used to analyze the research variables. The results showed no significant difference in the amount of IL-6 between the EAE group and the swimming training group, but the amount of IL-10 in the swimming training group showed a significant increase compared to the EAE group. The ratio of IL-10/IL-6 values between the swimming training group and the EAE group was also not significant. It seems that moderate-intensity swimming aerobic exercises, without changing the pro-inflammatory factor, along with increasing the anti-inflammatory factor IL-10, can lead to an improvement in the balance of the inflammatory index and a reduction in fatigue in the EAE group and the swimming exercise group.
