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The Effect of Exhausting Exercise Induced Fatigue on the Double-Leg Balance of Elite Male Athletes
Abstract
Journal of Social Sciences 5 (4): 445-451, 2009
ISSN 1549-3652
© 2009 Science Publications
Corresponding Author:
Khodadad Letafatkar, Department of Sport Injuries,
Faculty of Physical Education and Sport Sciences,
University of Tehran, Tehran, Iran
445
The Effect of Exhausting Exercise Induced Fatigue o
n the Double-Leg Balance of
Elite Male Athletes
1
Khodadad Letafatkar,
2
Mohammad Hossein Alizadeh and
3
Mohammad Reza Kordi
1
Department of Education and Sport Science,
2
Department of Sport Injuries: Physical Education, F
aculty of Sport Science,
3
Department of Exercise Physiology: Physical Educati
on, Faculty of Sport Science,
University of Tehran, Iran
Abstract: Problem statement:
Fatigue is a complex phenomenon that can be descri
bed as a time-
dependent exercise-induced reduction in the maximal
force generating capacity of a muscle. The aim
of the present study was to examine the effect of e
xhausting exercise induced fatigue on the double-le
g
balance of elite male athletes.
Approach:
This study included 30 apparently healthy young ad
ults
(handball and basketball professional players), 15
subjects in the control group (15 men with mean age
23±2.1 years old, Body Mass 82±1.3 kg and Body Heig
ht 181±9.7 cm) and 15 subjects in the
experiment group (15 men; age 23.1±2.2 years old, m
ean weight 81±0.9 kg and mean height 183±7.4
cm), matched evenly for age. In this study RAST tes
t used for fatigue protocole. Biodex balance system
and lactometer used for evaluation of balance and b
lood lactate level (respectively). For statistical
analysis, Pearson correlation coefficient, paired t
-test and sample t-test were used.
Results:
Results
revealed that there aren’t any significant main eff
ects for time, such that double legged balance
performance was maintained throughout the trial. Th
ere aren’t any significant main effects for time in
the mean lateral deflection of the biodex platf
orm. However, there was a significant main effect
(p = 0.091) in the mean anterior-posterior deflecti
on. The mean deflection was significantly reduced,
i.e., toward the anterior direction, at the end of
each half relative to all other time points. Hence
there
wasn’t a significant relationship between lactate
acid accumulation and variations of stability indic
es
(r = -0/661, p<0.05). The balance index was signifi
cantly lower for standing with eyes open compared
with eyes closed. The sensorimotor system normally
uses inputs from three afferent systems:
vestibular, somatosensory and visual. When one of t
hose systems (somatosensory) is impaired, the two
intact systems compensate for the impaired one to s
ome extent. Therefore, balance index in the eyes-
closed situation becomes higher compared with eyes
open.
Conclusion:
Balance was maintained (in
eyes opened situation) and this shows that balance
have a little decreases in double leg stance in
professional athletes.
Key words:
Exhausting exercise, fatigue, balance
... The remaining two senses usually compensate for a defect in one sense; the remaining senses must provide accurate and sufficient information to maintain balance [1,8]. Researchers now hypothesize that factors such as exercise and training, including perturbation exercises, can compensate for poor balance by involving the sensory systems in people with visual impairment. ...
Background and Aims: Perturbation training is a type of exercise in which participants frequently experience loss of balance to practice and improve control of balance reactions. Due to postural control impairment in blind people, this study aimed to investigate the effect of 4-week perturbation-based balance training on risk of falling, movement function, and balance in people with visual impairment. Methods: In the current, 30 men with absolute visual impairment were randomly divided into control (n=15) and experimental (n=15) groups. The experimental group performed perturbation exercises for four weeks and three sessions per week for 60 minutes. To evaluate the static balance of the modified stork test, the dynamic balance of the Berg balance tests, the movement function of the Tinetti test, and the fall risk of the functional reach test before and after the training intervention were used. Data were analyzed using an independent t-test and repeated measures analysis of variance at the level of α=0.05. Results: The results showed that the experimental group had an increase in the mean scores of static balance (P=0.001), dynamic balance (P=0.001), movement function (P=0.001), and decreased risk of falling (P=0.001) and is significantly better than the control group. Also, in the post-test, the findings of intragroup changes showed that the experimental group had a more significant effect on increasing balance, increasing movement function, and decreasing the rate of falling than the control group (P<0.05). Conclusion: According to the results of the present study, the use of perturbation exercises improves balance, increases the level of movement function, and reduces the risk of falling in blind people. Due to the positive effects of exercises and the benefits of this type of rehabilitation, it is recommended that this rehabilitation program be performed on the blind and visually impaired. Sports instructors are advised to use the balance-based perturbation exercises in this study and other exercises for people with visual impairment to increase their fitness.
... Does exercise induce an increase in afferent/efferent nerve impulses to and from muscle spindles around the ankle leading to improved joint position sense? It is suggested that handball and basketball players perform proprioception drills both in the rested and exercised state (Letafatkar et al., 2009). In fact, thoughts influence emotions, which in turn influences the behavior or performance: Thoughts -Emotions -Performance. ...
Problem statement: At the behavioral manifestation of acts of physica l education class at university is motivation. Purpose: Modeling the characteristics of personality and motivation of medical student's development following the establi shment of an appropriate methodology to act in university physical education lessons by developing and implementing a strategic program included in organization, management and conduct training pr ocess-education, the means of action game- specific sports: Basketball, handball and volleybal l. Approach: Study method bibliographic information, teaching observation, investigation me thod and experimental method, statistical and mathematical method. In different situations create d by practicing sports games shows a different reactivity of the students. Motivation explains why a behavioral act may have a special significance for a student, while the other has a meaning very w eak, sometimes absent altogether. The mechanisms regulating behavior of students who practice sports games have motivation that makes important link meaning actions of regulatory system s. One can say that motivation as a key feature of competition, combining dynamic factor activity v arious elements that go to most intimate corners of the human being. The dimensions of motivation in clude: goal setting, pulse power, perseverance, hope of success, fear of failure, independence and status oriented. Results and Conclusions: Following testing of the AMI at endpoint for experi ment group compared with control group was found to increase motivation of following variables : competitive orientation (4.19), fearlessness (3.39), safety success (3.29) preference for diffic ulty (3.21), self-control and self-discipline (3.05 ). Fundamental components of the game sports (technique, tactics, individual and collective actions) are a complex structure means that it acts on motor ic behavior, psycho-motor and the task-oriented motivation towards achieving goals, motivation to e lement of time and self-determination of students. Recommendations: Experimenting new curricula to the educational proc ess of physical education students of medical, dental and pharmacy, adapting its content according to themes, can lead to the sample improvements in parameters teste d experimentally.
Quantification of dynamic balance is often necessary to assess a patient's level of injury or ability to function in order to initiate an appropriate plan of care. Some therapists use the star-excursion test in an attempt to quantify dynamic balance. This test requires the patient to balance on one leg while reaching with the other leg. For the purpose of this study, the reach was performed in four directions. No previous researchers have attempted to evaluate the reliability of this test. Twenty healthy subjects between the ages of 18 and 35 years participated in this study. During two testing sessions, each subject was required to perform five reaching trials in four directions. Reliability estimates, calculated using the intraclass correlation coefficient (2, 1), ranged from 0.67 to 0.87. Six duplicate practice sessions were suggested to increase this range above 0.86. Task complexity may account for the moderate reliability estimates. Subjects should engage in a learning period before being evaluated on the star-excursion test.
Objective: To quantify the influence of soccer-specific fatigue on functional stability. Participants and design: Ten male semi-professional soccer players completed a 90 min treadmill protocol replicating the activity profile of match-play with a passive 15 min half-time interval. Main outcome measures: At 15 min intervals players completed a 30 s single-legged balance task on an unstable platform. Balance performance was quantified as a stability index and the mean deflection of the platform. Results: There was no significant (P>0.05) main effect for exercise duration in the stability index, suggesting that balance performance was maintained throughout the simulated match. However, the mean deflection of the platform was significantly (P<0.05) shifted toward anterior displacement during the last 15 min of each half. Conclusion: A change in balance strategy was evident during the latter stages of match-play, which may increase injury risk. It is recommended that soccer players perform proprioception training in the rested and exercised state to further develop neuromuscular control.
Proprioception was quantified in a group of patients who had documented complete ACL tears. Threshold to detection of passive change in position of the knee was measured using a well-described test. Eleven pa tients with arthroscopically proven complete ACL tears and findings consistent with moderate to severe anter olateral rotatory instability were tested. Testing was done within the 30° to 40° range of knee flexion. Patients were blindfolded and the injured and uninjured knees were tested in random sequence so that the normal knee could serve as an internal control. Testing was also done in a blind manner, i.e., the examiner did not know which knee had been injured. An age- matched control group underwent identical testing. Po tentially significant variables such as age, time from injury, and degree of rehabilitation as measured by thigh circumference and isokinetic testing of the knee were included in a multivariate analysis.
Control subjects demonstrated virtually identical threshold values between their two knees, the mean variation being less than 2%. The test group, however, showed a significantly higher mean threshold value for the injured versus the noninjured knee (P < 0.01), the mean variation being over 25%. Multivariate analysis demonstrated that changes recorded in the propriocep tion of the injured knee were attributable to the loss of the ACL rather than to other variables. Patients who have complete ACL tears and moderate to severe rotatory instability may also experience a decline in proprioceptive function of their knee.
The management of ligamentous injuries to the ankle is controversial. Neither the methods for classification and diagnosis, or the procedures for treatment are clear cut.
Ankle sprains are a common occurrence, with the majority involving the lateral ligament complex. Within this complex, the anterior talofibular ligament is injured most frequently, usually while the foot is in the plantar flexed position.
Ankle injuries can be diagnosed through physical exam, including the anterior drawer test and/or a stress exam, or through roentgenographic evaluation. The purpose of the stress roentgenogram is to measure the degree of talar tilt. However, it does not always yield consistent, reliable results. This inconsistency has led to the use of arthrography. There is debate over its use as well, however
Ankle sprains can be classified into three groups, according to functional loss. Treatment for first and second degree sprains is usually non-operative. The best approach to Grade III sprains is debatable. The issues in the treatment of Grade III sprains are first, whether treatment should be operative or non-operative, and second, whether non-operative treatment should emphasise immobilisation or mobilisation. Brostrom’s work is cited as noteworthy. He recommended adhesive strapping followed by mobilisation as the treatment of choice, and reserves surgery for cases of chronic instability. Results demonstrated that strapping yielded shorter disability periods, while surgery produced less instability. The prevention of functional instability is a major concern in the treatment of ankle injuries.
There is no consensus for treating a lateral ligament rupture. The authors suggest immobilisation followed by a rehabilitative programme. Three methods of immobilisation are plaster casting, adhesive strapping, and the air-stirrup. The physiological mechanism of cryotherapy and thermotherapy are discussed briefly and recommendations for their use are provided. Aspiration is also discussed.
Loss of motion is designated as a primary cause of chronic pain and reinjury, and exercises intended to restore range of motion are provided. Exercises aimed at restoring strength and proprioception are also presented. This allows for return to activity and serves to prevent reinjury.
The purpose of this study was to investigate the effect of endurance activities designed to simulate the physiological demands of soccer match-play and training, on leg strength, electromechanical delay, and knee laxity.
Eight recreational soccer players completed four exercise trials in random order: 1) a prolonged intermittent high intensity shuttle run (PHISR) which required subjects to complete a total distance of 9600 m in a form simulating the pattern of physical activity in soccer match-play (activity mode; rest-to-work intervals; approximately 90 min duration), 2) a shuttle-run (SR), (3) a treadmill run (TR) which required subjects to complete an equivalent distance at a running speed corresponding to 70% VO2max, and 4) a control condition consisting of no exercise.
Results from repeated measures ANOVA revealed significant condition (PHISR; SR; TR; control) by time (pre; mid; post) interactions for peak torque (PT: knee extension and flexion: 1.05 rad.s-1), EMD and anterior tibio-femoral displacement (TFD) (P < 0.05). Impairment to indices of knee joint performance was observed in PHISR, SR, and TR trials. The greatest decrement occurred in PHISR and SR trials (up to 44%). Knee extensor and flexor strength performance near to full knee extension (0.44 rad knee flexion) was not changed following the functionally-relevant endurance activities.
Even though strength performance near to full knee extension was preserved following acute endurance activities, the risk of ligamentous injury may be increased by concomitant impairment to EMD and anterior TFD.
Ten patients with chronic unilateral functional lateral instability of the ankle were evaluated using the Biodex Stability System. This system uses a multiaxial testing platform which can be set at variable degrees of instability. Patients are then tested for their ability to “balance” the platform during single-limb stance, and a stability index is electronically generated. This stability index is believed to be an objective measurement that correlates with proprioceptive status of the ankle.
Instability of the ankle was confirmed in all 10 patients, using stress radiographs. Two levels of platform stability were tested. With the platform in its most stable configuration, there was minimal difference between the previously injured and the uninjured ankle. With the platform set to permit up to 20° of tilt in any plane, 6 of 10 patients had more difficulty balancing the platform with their injured ankle (higher stability index). This preliminary study suggests that the Biodex Stability System may be a useful tool in trying to objectively measure proprioceptive function.