Research in Sport Medicine and Technology

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Introduction: Balance is a key component of motor control and plays a crucial role in maintaining postural stability during dynamic tasks such as landing and changing direction. Time to stability is a sensitive indicator of neuromuscular efficiency in restoring balance after mechanical perturbations.
Purpose of study: The purpose of this study was to examine the effects of balance training with and without stroboscopic glasses on TTS in physically active individuals.
Methods: In this Randomized Controlled Trial study, 39 physically active men aged 18–30 years were randomly assigned to three groups: balance training with stroboscopic glasses, conventional balance training, and control. Participants completed six weeks of progressive balance exercises. TTS during single-leg landings from 30, 50, and 70 cm was measured using a force plate. Data were analyzed using ANCOVA and Bonferroni post hoc tests with a significance level of 0.05.
Results: The results of the analysis of covariance (ANCOVA) indicated that both training groups showed a significant improvement in time to stabilization compared with the control group (p < 0.05).A significant main effect of group was observed at 30 cm (η² = 0.34, F = 8.40, p = 0.001), 50 cm (η² = 0.25, F = 5.33, p = 0.010), and 70 cm (η² = 0.30, F = 6.96, p = 0.003).

The reduction in time to stabilization was greater in the stroboscopic eyewear group at the 50- and 70-cm landing heights and was accompanied by larger effect sizes. At the 30-cm height, both training groups demonstrated similar improvements.
Conclusion: Intentional visual perturbation using stroboscopic glasses enhances reliance on proprioceptive and vestibular inputs, improving dynamic balance control. Integrating stroboscopic glasses into balance training programs may be an effective strategy to enhance performance and reduce the risk of lower-limb injuries in athletes.
Keywords: Balance training, stroboscopic glasses, time to stability

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Muscle imbalances in the shoulder are a weakness in the external rotator cuff muscles compared to the internal rotator cuffs, in which the weakness of the external rotator cuff muscles is a risk factor for volleyball players' shoulder injuries. Shoulder dyskinesis can be caused by imbalance of the scapula stabilizing muscles, which improves with muscle coordination the aim of this study was to investigate the effect of perturbation training on eccentric strength of external rotators and scapular kinematics. Twenty-four male volleyball players with a score of less than 30 on CKCUEST test participated in this study, which was randomly divided into two groups of experimental and control. The eccentric strength of the external rotator cuff muscles was measured using an isokinetic at 120 degrees per second. Scapular upward rotation also measured with a dual inclinometer at 45 °, 90 °, 135 ° and the end range of motion of the shoulder abduction. Comparing the experimental and control groups, a significant difference was observed in the shoulder external rotators eccentric strength. There was a significant difference only in 135 ° of scapular upward rotation. In other angles, no significant difference was observed between the two groups. The results showed the positive effect of perturbation training on the eccentric strength of external rotators and scapular upward rotation in arm abduction; therefore, coaches and volleyball players can be advised to add these exercises to their training programs to increase performance and prevent shoulder injuries.
 

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Testosterone enanthate increases muscle growth and athletic performance but is associated with oxidative stress and tissue damage. This study aimed to investigate the effect of propolis on oxidative stress markers induced by testosterone enanthate in the kidney tissue of female Wistar rats undergoing resistance training. Twenty-two 8-week-old female rats, weighing 208.22±14.17 g, were randomly divided into three groups: 1) resistance training + placebo (n=6), 2) resistance training + testosterone enanthate (n=8), 3) resistance training + testosterone enanthate + propolis (n=8). The rats underwent an 8-week resistance training protocol involving ladder climbing (five days per week). Testosterone enanthate was administered at a dose of 20 mg/kg body weight per injection, and propolis was administered at a dose of 400 mg/kg body weight by gavage (each three times a week). The levels of superoxide dismutase (SOD), glutathione peroxidase (GPX), and malondialdehyde (MDA) in kidney tissue were measured by spectrophotometry. One-way ANOVA and Bonferroni post hoc tests were used for statistical analysis. The results showed that testosterone enanthate significantly decreased GPX and SOD levels and increased MDA levels. Propolis consumption led to a relative reduction in these oxidative stress markers, demonstrating its potential antioxidant effects.

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Introduction and aim: The purpose of this study was to Comparison of the effect of neuromuscular trainings with and without supervision on core stability and proprioception and pain of housewives' with nonspecific chronic low back pain.
Methodology: In this semi-experimental study 30 housewives from Qazvin city selected and randomly divided into three experimental groups. (neuromuscular trainings without supervision: age: 46±10/4 yr., Height:154/7±8/7 cm., weight:74/8± 6/2 kg), neuromuscular trainings with supervision (age: 40/7±9/1 yr. Height: 161/9±5/9 cm., weight: 65/3±7/5 kg) And control: age: 46/4± 10/3 yr, Height:155/1± 8/8 cm., weight: 69/4± 10 kg)) with nonspecific chronic low back pain (age: 30-60 yr) Were affected. Training sessions held for 8 weeks under researcher supervision (3 session of 90 minutes per week). To assess pain and proprioception of trunk and core stability, Visual analogue scale (VAS), goniometer and McGill and Bearing-Sorensen test were used respectively. ANOVA was used to analyses data and for pairwise comparison, Tukey's test was used.
Results: Results of this study show that pain in two experimental groups (neuromuscular trainings with and without supervision) were significantly reduced compared to the control group (P=0.000), as well as deep sense and central stability in both neuromuscular trainings with and without supervision groups and these groups significantly increased compared to the control group (P=0.000), but there were no significant differences between neuromuscular trainings with and without supervision groups for all variables (p≥0.05).
Discussion and conclusion: According to the results it's recommended that these exercises, because of the minimum cost, when and where to focus on and execute people with non-specific chronic low back pain.

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Exercise training and rice bran have anti-inflammatory effects. However, the effect of combining the two interventions on inflammatory factors is unclear. Therefore, the present study aimed to investigate the effect of aerobic training and rice bran consumption on the levels of selected inflammatory factors in overweight men. Sixty overweight men were randomly divided into four groups (n=15): control, rice bran, progressive aerobic training, and training + rice bran. Progressive aerobic training was performed at an intensity of 60-75% of maximum heart rate for, 20-35 min, 8 weeks, with 3 sessions per week. Rice bran was consumed in an amount of 10 grams twice a day (before breakfast and before sleeping). Before and after the completion of the interventions, blood samples were taken and serum levels of CRP, IL-6, and TNF-α were measured by ELISA. Analysis of covariance with Bonferroni post hoc test was used to interpret the data. There were significant decreases in the levels of CRP, IL-6, and TNF-α with training and training + rice bran compared to the control and rice bran groups (p<0.05). The CRP and TNF-α reduction was also significant after rice bran consumption compared to the control group (p<0.001). Moreover, decrease in the levels of IL-6 (p=0.002) and TNF-α (p<0.001) in the training +rice bran group compared to the training group was also significant. The findings confirmed that aerobic training and rice bran consumption are effective in reducing inflammation, and there was a synergistic effect of rice bran supplementation and aerobic training.
 

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The study aimed to investigate the impact of gait retraining using verbal feedback on pain and peak vertical ground reaction force in runners with patellofemoral pain syndrome, a common treatment and prevention method for the condition that involves modifying movement patterns to ensure knee joint stability. The current research was applied, and a semi-experimental study method with a pre-test-post-test design was used. The statistical sample of this research was made up of 20 runners with patellofemoral pain syndrome who were identified by a physiotherapist using the Clark test and were randomly divided into two control and experimental groups. The experimental group performed eight weeks of running and three sessions per week along with the walking retraining protocol with verbal feedback from the researcher, while the control group did not receive any intervention to their exercise. The variables studied in this research were the pain factor and the peak vertical ground reaction force, which were recorded respectively using a visual analog scale and a Bartek dynamometer with a sampling frequency of 1000 Hz in both pre- and post-test stages. The results of the the mixed analysis of variance test with repeated measurements showed that the interactive effect of time on the group was significant and, the gait retraining protocol by verbal feedback reduced pain (P=0.000) and the peak vertical ground reaction force in the experimental group (P=0.003). The existence of differences in pain variables and peak ground reaction force during running confirms the need to use different strategies in the training of athletes. It is suggested that trainers have a special look at the gait retraining approach by verbal feedback to correct the movement pattern while running, in rehabilitation, and specialized exercises.
 

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 The purpose of this study was to investigate eight weeks of dynamic neuromuscular stabilization exercises on movement performance indicators, walking kinematics and lower limb damage in students with weak lumbopelvic control. Methodology: 30 female students with a mean age of 16.65±0.75 years, height of 161.80±4.11 cm, weight of 62.70±5.64 kg who had weak lumbopelvic control were purposively selected and randomly divided into two experimental groups n=15 and control groups n=15. The experimental group performed the neuromuscular for eight weeks, three sessions per week for 60 minutes, while the control group did not receive the intervention to assess lumbopelvic control a biofeedback device was used for jumping, static balance was used for stork test,  dynamic balance was used for Y test, landing error was used for landing Error Scoring System Test, and lower limb motor function was used for tests (single-leg jump test, triple jump test, 6 - meter jump test in time, and cross jump test results: The present study showed that the effect of DNS exercises on motor performance indices 0.012, gait kinematics 0.001, and lower limb injury 0.012 was significant P<0.05.
 

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Purpose: Weakness in physical fitness is one of the factors that reduce the quality of life, illness, and injury of the elderly. Elderly people who do physical exercises reduce the occurrence of falls and the risk of fractures, suffer from depression and dementia, and improve physical fitness. Therefore, the present study was conducted with the aim of comparing the effectiveness of eight weeks of Fall proof and combined training on the physical fitness of elderly women.
Methods: The subjects included 45 elderly women, who were randomly divided into three groups: control, Combination training, and Fall proof training. A pre-test and a post-test were conducted for all groups, which included the measurement of some physical fitness factors. Then, the experimental groups did an exercise program for eight weeks, three sessions per week, and each session lasted 60 minutes, and during this time, the control group did their daily activities.
Results: In this study, it was shown that a course of Combination and Fall proof training caused a significant increase in improving strength (P=0.001 and P=0.001), body composition (P=0.003 and P=0.001), static balance (P=0.001 and P=0.04), dynamic balance (P=0.001 and P=0.001), flexibility (P=0.01 and P=0.001) and cardiovascular endurance (P=0.001 and P=0.001) in the elderly and the effect of Combination training on muscle strength was more than Fall proof training (P=0.04). Also, in static balance and flexibility, Fall proof training was more effective than Combination training (P=0.08 and P=0.004).
Conclusions: Based on these results, it can be concluded that using both training protocols used in this study can be used to improve the level of physical fitness of the elderly. Based on these results, the two training protocols were not significantly superior to each other.
 

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This systematic review aimed to investigate the effectiveness of resistance training, particularly exercises designed based on 3D motion analysis, in improving muscle strength and balance function in elderly individuals with early knee osteoarthritis. A comprehensive search was conducted in PubMed, PEDro, Scopus, and Web of Science databases for articles published from January 2000 to December 2024. Selected studies were required to have utilized 3D motion analysis to assess movement deficits and design exercise programs. Out of 84 reviewed articles, 18 were chosen for final analysis. The results indicated that the majority of studies (86%) confirmed the effectiveness of resistance training in ameliorating knee osteoarthritis symptoms. Specifically, significant improvements were observed in functional balance (44% of articles) and reductions in knee pain (48% of articles). Furthermore, 33% of the studies reported superior efficacy for exercises designed based on 3D biomechanical analysis. These findings can significantly enhance the quality of life for patients and promote mobility safety in the elderly by reducing the risk of falls and improving joint stability. In conclusion, the findings suggest that innovative training approaches, particularly those incorporating 3D motion analysis, can play a pivotal role in optimizing rehabilitation and enhancing the quality of life for elderly individuals with knee osteoarthritis.
 

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Abstract
Purpose: Balance and gait are considered critical factors for the health of older adults. The aim of this study was to investigate the effect of 8 weeks of virtual reality (VR)-based training on balance and gait in older women. 
Methods: The statistical population of this study consisted of all elderly women with an average age of 75.5±3.39 and an average weight of 72.08±9.46 kg in Shahrood city. 30 people were selected conveniently and purposefully based on the inclusion and exclusion criteria. Then, they were randomly divided into two groups (15 people in the experimental group and 15 people in the control group). In the pre-test, the subjects' static balance was measured by the Sharpendramberg test, dynamic balance by the modified Star Balance test, functional balance by the Berg Functional Balance Scale test, and fall risk by the Dynamic Gait Index test. The subjects in the experimental group did virtual reality-based exercises for 8 weeks (3 sessions per week, each session lasting 30 to 45 minutes). Finally, all subjects were post-tested and the data obtained were used by paired t-tests for intragroup comparison and independent t-tests for comparing between-group changes at a significance level of p<0.05. 
Results: The findings of the present study showed that 8 weeks of virtual reality-based training significantly increased static, dynamic, and functional balance (p=0.022), (p=0.0001), and (p=0.0001), respectively. Also, the dynamic gait index was significantly improved in this group (p=0.0001). The results of the independent t-test also showed that a significant difference was observed in the variables of static (p=0.001), dynamic (p=0.04), and functional (p=0.015) balance and dynamic gait index (p=0.0001) between the experimental and control groups. 
Conclusions: The results of the present study showed that virtual reality-based exercises play a significant role in improving static and dynamic balance and reducing the risk of falls in the elderly. Therefore, it is suggested that this age group, by taking advantage of this effective training method, prevent balance disorders and subsequent adverse consequences that are inevitable with aging.

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Introduction: Blood flow restriction (BFR) has been shown to induce local hypoxia. Therefore, the purpose of this study was to investigate the effect of BFR-induced hypoxia on the angiogenic response to high-intensity interval exercise (HIIE). Methods: Thirty active young men (age =25.6±3.4) were randomly assigned to three groups (n=10 each): control, high-intensity interval exercise (HIIE), and high-intensity interval exercise with blood flow restriction (HIIE+BFR). The HIIE protocol consisted of 5 sets of 5×30-second high-intensity running intervals with 30-second rest periods. BFR was applied at 60% of each individual's optimal occlusion pressure in the lower limbs. Serum levels of VEGF, HIF-1α, MMP-9, and MMP-2 were measured as angiogenic markers. Statistical analysis was performed using ANCOVA with LSD post-hoc test, with the significance level set at α=0.05. Results: The data revealed that compared to both the control and HIIE groups, the HIIE+BFR group showed significantly greater increases in serum VEGF and HIF-1α levels (P=0.002 and P=0.019, respectively). However, no significant differences were observed among groups for MMP-9 and MMP-2 levels (P=0.318 and P=0.101, respectively). Conclusion: This study demonstrated that combining HIIE with BFR can enhance the angiogenic response through increased VEGF and HIF-1α levels, but does not significantly affect MMP-2 and MMP-9. These findings support the notion that BFR-induced local hypoxia may serve as a complementary stimulus for improving vascular adaptations.

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The foot represents a small base of support as an important biomechanical parameter that the body maintains balance. It is assumed that postural stability performance could be affected by even minor alteration in the support surface in upright standing position. Therefore, the purpose of this study was to determine if individuals with different foot types would demonstrate differences in static postural stability performance. Sixty adolescent girls were categorized into three groups depending on their bilateral foot types namely, pronated, supinated and rectus feet. Foot types defined by Navicular-drop measures. We measured static stability performance with the Balance Error Scoring System once firm and once on a foam surface. ANOVA with repeated measures was employed for statistical analyses (p<0.05). Results showed no significant differences between individuals with pronated and rectus feet were revealed for static stability scores while standing on the firm surface. Pronated group showed a poor balance performance while tested on the foam surface in comparison with rectus group. Subjects with supinated feet had a poorer static stability performance on both firm and foam surfaces than others groups. These results demonstrated that static stability performance could be affected by foot type

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MS is a lifelong disease that could involve the person in different forms. Knowing balance characteristics of different types of this chronic disease helps the specialists for controlling their complications. The purpose of this study was to recognize static and dynamic balance of different type of MS and to compare MS patients with healthy individual. 54 MS women in three groups (27- Relapsing-Remitting, 16 secondary progressive, 11 primary progressive), 20 randomly healthful women have been elected. Static and dynamic balance test (dynamics with 8 degree), overall, lateral and anterior/posterior have been done by Biodex machinery from four groups. Kolmogorov-Smirnov inferential statistic test used to assess the normality of the data distribution and the chi-square test was used to examine the relationship within and between types of MS disease with normal. The parametric statistics tests including independent t-test applied at threshold 0.05. According to results, there are meaningful difference between overall balance index in static balance in different types of diseased women affected by MS (p<0.05). The Primary Progressive groups have weak, and Relapsing-Remitting MS group have strong static balance in comparison with other groups. Furthermore, meaningful difference shown through overall balance index in static mood in different type of disease women affected by MS (p<0.05). Difference between static balance index and dynamic was meaningful between control group and MS disease. Considering the findings of the study, women affected by relapsing-remitting type have better dynamic & static balance rather than progressive types. Static & dynamic balance in affected women was weaker than healthy women.

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Training exercises are known to affect depressed girls condition, but the effect of regular exercise in exhilarating environments, in particularly on markers related to epinephrine metabolism in depressed girls are not well known. The purpose of the present study was to determine effect of the 6 weeks of intermittent walking in water on urine MHPG sulphate and Hamilton scale in the depressed girls. Twenty-four of girls' students, who suffering from moderate depression, randomly divided into exercise and control groups. The subjects in the training group performed the progressive walking exercise of 60-70% of maximal heart rate, 3 times a week and for 6 weeks. The Hamilton scale and urine samples were measured in before and after the mentioned exercise protocol. The urine MHPG sulphate was measured by HPLC-flurometric detection method. The data were analyzed by t- student and the Pearson correlation coefficient tests at p≤0/05 levels. The results showed the 6 weeks of exercise resulted in significant increase in the urine MHPG sulphate and VO2max and significant decrease in Hamilton scale compared to the control group. Furthermore, there was a significantly positive correlation between the urine MHPG sulphate and VO2max (r= 0/65). However, there was a significant reversely correlation (r= - 0/52) between the urine MHPG sulphate and Hamilton scale in prediction of depression. These results emphasize the role of regular physical exercise, particularly in exhilarating environments in the promotion of depression state. Also, in some conditions can be used Hamilton scale instead of the urine MHPG sulphate detects.

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In this study, the effects of vibration training on physical fitness factors in elderly
females investigated. 40 subjects with age 61/09±6/24 yrs, weight 65/84±11/98
kg, height 156/99±5/06 cm and body mass index 26/64±4/23 kg/m2 voluntary
participated in this study and were divided in vibration (n=16), non-vibration
(n=14) and control (n=10) groups. The vibration group performed exercises on
the device (JET VIB) for 10 days with 35-40Hz frequency, 12 mm amplitude and
eight positions. The non-vibration group performed the same exercises (in
position, set and time) on the turned off device. The control group did not
exercise during the study. Leg and hand strength (dynamometer), flexibility (sit
and reach), balance (standing time on one leg) and body composition (skinfold
with caliper) were measured. Paired sample t test and one way ANOVA used
for data analysis. In within group analysis, vibration group showed significant
increase in right (p=0/02) and left hand strength (p=0/01), leg strength
(p=0/008), Flexibility (p=0/005) and left leg balance (p=0/006). In non vibration
group just significant increase in right hand strength (p=0/01). There was no
significant change in control group. Between group analysis showed, significant
increase in right (p=0/006) and left hand strength (p=0/003), leg strength
(p=0/004) and left leg balance (p=0/01) in vibration group comparison with to
other groups. There was no significant change in right leg balance (p=0/),
Flexibility (p=0/005) and body composition in any of groups. Due to the results
short term vibration training can improve flexibility, strength and balance in
elderly subjects.
 

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In order to compare the acute effects of OR and Megabasic (two energy drinks)
by a placebo, 24 volunteer male athletes (age: 24.3±2.03 yrs, height
173.56±7.02cm and weight 75.43±3.07kg) participated in two consecutive
RAST tests by 40 min rest interval in between within 3 randomly divided groups.
There were six times blood sampling (before and also 2 and 4 min after than
both tests) in order to analyze blood lactate and PH levels (Gas analyzer) and
also the anaerobic indices (Peak, mean and mean power) was calculated. The
data corresponding to each group’s blood factors was compared by ANOVA for
repeated measurements (post hoc: Bonferoni), their changes between two
consecutive RAST tests was compared by ANOVA (post hoc: LSD) and
anaerobic power data for each group was compared using pair sample t test at
0.05 significance level. Results: Significant changes were observed in blood
lactate and PH levels during repeated measurements in both RAST tests at all
groups (p<0.05). There were also significant differences in the amount of the
changes in between the measurements between groups (p<0.05). Additionally,
Peak and min power only significantly increased in second RAST test rather
than first one and mean power also significantly decreased in both energy drink
groups between the first and second RAST tests (p<0.05). Conclusions:
Consumption of the OR can affect anaerobic power during short term repeated
interval activities. However, there are evident differences in between multiple
brands of energy drinks with regard to the amount of the modifications in the
changes at both blood lactate and PH levels, in spite of this fact that there is
any consensus in this field because of the lack of comprehensive researches.

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The purpose of the present study was to compare some antropometric characteristics of 11-14 years old male students in high, average and low Socio-economic Status. 610 students from public schools in three educational districts of Isfahan were randomly selected by clustral method. Then the Subjects were located in three low, average and high Socioeconomic status groups. Height, weight, triceps and culf skinfold thichnesses were measured. Result showed that there were Significant differences between three groups in weight, triceps and culf skinfold thickness, sum of two skinfold thickness (culf and triceps) and percent body fat. Also there were no Significant differences between three qroups in BMI and height. Result showed that weight of students with high socioeconomic Status was greater than the Students with average and low socio economic Statues. Also the skinfold thickness of triceps, calf and percent body fat of students with high socioeconomic Status were greater than students in low socioeconomic status. It seems that the childreen in high socioeconomic status have more weight and fat than children in low socioeconomic status. Other researches have Concluded that the girls in high socioeconomic status have lower percent body fat compare to children in low socioeconomic status.

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This study investigated the effect of water immersion and passive recovery on blood lactate and subsequent swimming performance. Ten trained female swimmers, age (17.8 ±2.2), height (164.55.8 cm), weight (59.29.9 kg), %BF (22.41.7) and BMI (21.85.4kg/m2) completed three experimental trials differing in 15 min recovery intervention three times a week with 48 hrs distance: land (sitting near the pool) (PAS), contrast water therapy (CWT) (alternating hot 40,2 min/cold 23,1min) and cold water immersion(CWI)(23 ). Before and after 100meters front crawl and each three
minute during of recovery blood lactate, heart rate and skin temperature were
recorded. Participants repeated 100meters front crawl after the recovery.
Repeated measure and LSD were used for data analysis. In all statistical
analyses, the threshold for significance was set at (p≤0.05). Results showed
that Heart rate decreased significantly in CWI toward PAS. Lactate removal was
largest in CWT compared to the PAS. Skin temperature and fatigue decreased
significantly after immersion and significant difference was observed in
subsequent performance after immersion toward PAS. So it seems immersion
conditions, can enhance quality of recovery.

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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.