Research in Sport Medicine and Technology

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

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.

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.

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.
 

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.

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.

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.

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.

Objective: KinesioTaping is a method for rehabilitation of patients and athletes.
The efficacy of taping to enhance proprioception precision and balance has
been studied. The effects on skin sensory receptors and limb consciousness
are mechanisms of taping but there is an important question that if the persons
pay attention to other task the effectiveness of taping is still exists or not?
Materials and Methods: Ten healthy persons with average age of 28±3/3
years¸ height of 161±4/1cm and weight of 52±14/1kg participated in this study.
The index of stability was assessed in five conditions standing on the BIODEX
ISOKIETIC Instrument. The examination five conditions were as following
order.1-standing barefoot for 20 second (dominant foot).2-standing and dual
tasking for 20 second.(Reverse numbering from digits between 100-150). 3-
standing with taping on proneal muscles for 20 second.4-standing with taping
and dual tasking for 20 second.5-first condition was repeated. Results:
However¸ there was not any significant difference between the Stability Index
(SI) of the test conditions in this study but the pattern of changes showed that
when volunteers performed dual task with or without tape the stability index
improved. Improvement of SI with taping was not considerable. Conclusion:
Taping has a little positive effect on stability but effects of dual tasking were
coincided with the non-linear U-shaped pattern of dual tasking effect. It means
that stability was improved by the dual tasking used in this study which may be
too light to decrease stability of the subjects. This finding showed that triple
reverse numbering is not enough difficulties to attention demand interferes the
stability of the subjects.

Background/aim: Many studies were shown the effect of type's recovery on
performance. Active recovery has been reported by some to promote greater
exercise capacity, while others have not confirmed these results. The aim of this
study was to determine the effect of three types of recovery during repeated
high-intensity endurance training on blood buffering capacity and H+
regulation. Design/method; the statistical population of this research was
physical education students studying at Tarbiat Moallem University of Tehran.
Ten students participated in this study. Each individual completed a special
questionnaire to be healthy during the study period. On subsequent days they
performed repeated high-intensity endurance test (RHIET).The RHIET
consist of four bouts about 2; 30 minutes. Recovery periods of 5minutes were
allowed between bouts. RHIET differed in the kind of activity performed during
the recovery periods; Gouging at 63% maximum heart rate, stretching exercises
and lying supine. A sample of 5CC blood artery obtained from each individual
immediately after the last recovery period. Blood sample were sent to the
laboratory for homology test. Their buffering capacity was measured by
assessment of the following parameters: PH, PCO2, BB, HCO3
-, BE, O2-sat.
The ANOVA Repeated-Measures was use to analyze the data by spss16.
Results; Significant differences were shown between the active recovery and
the stretching exercises recovery and between the inactive recovery and the
stretching exercises recovery on PH, BB and between active recovery and the
inactive recovery on O2-sat (P≤0/05). There were no significant differences
between the active, inactive and stretching exercises recovery on HCO3
-, PCO2
and BE (p≤0/05). Conclusion; Therefore, this study has show that the inactive
recovery improve buffering capacity compared to the stretching exercises and
the active recovery. This finding is agreement with research dating Argyris
(2004), DuPont (2004), Buchheit (2009) and in agreement with research dating
Dorado (2004). Nick Draper (2006), De Geus Bas (2007). Alveolar gas
exchange can therefore increase due to slower heart rate and slower breathing
rate. The kidneys removal H+ and reabsorption HCO3
-. The body's metabolism
becomes lower and producing metabolic is decrease. Temp whole body
(muscle, blood) is decrease; oxygen is combined with the hemoglobin strongly.
Hence, PH is increase and buffering capacity is improved.

This study is aimed to evaluate the effect of 4 weeks swimming training with
chest wall restriction on aerobic power, cardio-respiratory functions and
swimming performance of elite female swimmers. 24 elite female swimmers
volunteered to participate in this study and were randomly divide into two
groups: Control (swimming training without chest wall restriction) and
experimental group (swimming training with chest wall restriction). Both groups
were in a monthly swimming program (they trained 3 times a week for a total of
4 weeks). They swam almost 3.5 to 4 km/d with 70 – 85% of HRmax. Aerobic
power, pulmonary parameters, time to exhaustion and swimming performance
were measured. To analyze data, student t test was used. The results showed
that Time to exhaustion increased in group training with chest wall restrictor
(P=0/012). T-20 test results showed improvements in experimental group. No
significant difference was observed in VO2max, MVV, FVC, and FEV1/FVC in
two groups. Also there was no significant difference between the groups.
Therefore, the results showed that using chest elastic band in order to impose
more stress on respiratory muscles during exercise leads to some adaptations
in these muscles and it is associated with some improvements in exercise
performance.

Abstract
The purpose of this study was to investigate the relationship between success
on an over 6000m summit and results of physical fitness tests that normally are
performed by mountaineering federation to select mountaineers for climbing
high mountains. Therefore in this study, relationship between the results of
these tests in 8 female climbers (age, 34.4±8.7year, height, 163.9±5.9cm, body
mass, 60.6±3.8kg) and their performance and success while ascending Mera
Peak (6654m) were assessed. Results showed that none of the cooper test,
long jump, chin up, and sit up tests; and also weekly training volume, age, body
mass, BMI, and percent of body fat were significantly correlated to climbing
ability at altitude, summiting, or incidence of acute mountain sickness.
Summiting was only related to climbing ability over 5000m in 2 days before
summiting (p=0.039) and sleeping history over 3000m (p=0.002). In conclusion,
physical fitness near to sea level could not guaranty climbing ability, summiting,
and healthy mood at high altitude. Climbing and sleeping history at high altitude
may be better criteria for a successful upcoming climb.

The purpose of this study was to determine the effect of two different intensities
of physical activity on circulating endothelial progenitor cells (EPC) in healthy
young women. For this purpose, 15 female students from volunteers were
randomly selected via questionnaire (group 1: mean age 22 ±1/8 years, BMI
20/81±1/91 kg/m2, n = 8. group 2: mean age 21 ±1/5 years, BMI 20/38 ± 1/66
kg/m2, n = 7). Each group ran 30 minutes at their particular (group 1: ٧0%
HRmax & group 2: ٨5% HRmax) activity on treadmill. Blood samples were
taken from all subjects for measurement of circulating endothelial progenitor
cells CD34+ and same Isotype control, white blood cells and platelets before
and10minutes after the test. The related T-test (paired) were used for
comparisons within a group , to compare variables between groups were used
one way of variance analysis (ANOVA) for determining the relationship between
variables were used Pearson correlation coefficient. Statistical significance was
accepted as a P value of <0.05. Results of this study showed that both
intensities of physical activity increased significantly the number of EPC, WBC
and Plt, this affects was higher in intensity 85% HRmax, but was not statistically
significant. Just was observed significant association between EPC and platelet.
In summary, can be expressed that physical activity with intensity 70% and 85%
HRmax can increase re-enthotelialisation due to mobilization of EPC, and with
attention to significant association between EPC and platelet these cell
mobilization may serve as a physiologic repair or compensation mechanism in
acute inflammatory injury.
 

The purpose of this study was to collect the norm of bio-energetic
characteristics of male and female elite and advanced Badminton players in
Iran based on gender differences. This is a descriptive research of the kind of
normative survey. Statistical population of the research includes all elite and
advanced male and female Badminton players in Iran during 2010 including 128
elite and advanced players, 64 male (mean age 19.92 + 3.4 yr. height 176.53 +
6.13 cm, weight 70.46 + 6.77 kg and competitive experience 9.27 + 2.68 yr) and
64 females (mean age 17.00 + 2.4 yr, height 163.90 + 5.87 cm, weight 56.18 +
5.75 kg and competitive experience 6.27 + 1.55 yr). The statistical sample was
equal to the statistical population. Regarding the specific characteristics and
demands of Badminton, aerobic power, alactic anaerobic power and lactic
anaerobic power were measured. Also based on the distribution of the obtained
scores, frequency tables and percentage points of the players were drawn
based on gender differences in order to collect the related norms, using spss-15
software. Then according to the percentage norm and Likert scale, players'
performance was classified. One sample t test was applied to compare bioenergetic
characteristics of national and world elite Badminton players. The
results of this study indicated that the average aerobic power of Iranian male
and female elite and advanced badminton players, respectively 55/16 and 44/05
ml/kg.min are significantly lower than the values for world male and female elite
badminton players which are 63 and 50 ml/kg.min (p  0.01). also, the average
of sergeant vertical height of Iranian male and female elite and advanced
badminton players accounting for 63 and 48 centimeters are again significantly
lower than the reported values for world male and female elite badminton
players as 75 and 56 centimeters (p  0.01) but lactic anaerobic power of male
and female Iranian elite and advanced badminton players was in a goodsituation. The results of study highlight an urge to review and pay more
attention to designing professional practices in order to improve and develop
the aforementioned factors.

The purpose of this study was to consider the effect of eight weeks aerobic
and strength training on serum PTH, calcium, albumin and alkaline
phosphatase in postmenopausal women.35 post menopause women, (55-70
years), of Jahandidegan center of Tehran were selected and randomly divided
to three groups as aerobic (n=12), strength (n=13) and control (n=10) groups.
Aerobic training program include jogging and aerobic movements, with 60-
70% MHR intensity(8 weeks, 3 times per week, 40minute per session), And
Strength training program with emphasize on main muscle groups (8 weeks, 3
times per week, 1 hour per session),with30-40%1RM,8-10rep,1set to 60-
80%1RM,8-10rep,1set . One way analysis of variance (ANOVA) used to
compare differences between groups. The results showed that PTH and
alkaline phosphatase significantly increase after aerobic and strength training
in comparison with control group (P≤0.05). But the significant difference was
not observed between these two groups. No significant difference was
observed in serum calcium between two trained and control groups (p≥0.05).
However a significant decrease was observed in strength group (P≤0.05).
Furthermore, the significant change was not observed in albomin after training
program. Increase in PTH and alkaline phosphatase concentrations in normal
range seem to promote anabolism procedure of bone formation. The result of
this study shows that both two type of training have same effects on bone
markers and hormonal factors.

Background: In sports such as handball, tennis and volleyball the player need to involve the great loads over his shoulders. In these sports, players are predisposed to overuse injuries. Infraspinatus syndrome’s meaning is the painless weakness and atrophy of this muscle that observe following Suprascapularis nerve neuropathy. In this investigation we want to survey the effects of a short term of progressive endurance-strengthening training and electrical stimulation on strength and electromyography in infraspinatus muscle. Method: 12 volleyball players with Infraspinatus syndrome were randomly divided to two groups: progressive endurance-strengthening training (6 persons, age 24/8±3/8, height 189/3±2/6, weight 83/8±7/9, sport background 9/4±2/5 and national team’s background 3/24±1/7) and electrical stimulation (6 persons, age 24/2±4/5, height 192/5±1/5, weight 86/2±6/4, sport background 8/5±4 and national team’s background 4/3±2/8). 20 persons of healthy players were considered to be as a control group (age 25/1±4/2, height 187/7±3/9, weight 75/6±7/1, sport history 9±3/8 and national team history 3/9±2/3), too. Therapeutic interventions performed for 8 weeks. Surface electromyography of infraspinatus and tress minor muscles and maximal isometric strength of external rotator muscles were measured before and after interventions. Data analyzing performed by SPSS.12 and we used of Paired sample T test and one-way ANOVA. Confidence level considered to be 95% (P<0.05). Results: After eight weeks, maximal isometric strength of external rotators in both experimental groups was increased significantly, but there were observed no significant changes in IEMG and RMSEMG. Conclusion: Progressive endurance-strengthening training and electrical stimulation can result in increase of maximal isometric strength of shoulder external rotator muscles. But both therapeutic methods have no effect onelectromyograghic parameters in infraspinatus and tress minor muscles. It seems that we can't use of surface electromyography for detecting the effect of these protocols on above muscles (P<0/05).

Aim: The aim of this study was to determine the effect of basketball specific and general training on physical and physiological fitness in male basketball players trained. Methodology: The statistical population of this research was 18 basketball players trained invited to Asad Abad preparation camp. 12 players out of the total number participated in this study were ranked by fitness level and randomly assigned to a specific (N=6) and general training groups (N=6). Each player completed a special questionnaire to be healthy during the study period. The specific and general training groups have performed the trainings in interval model three sessions per week for 6 weeks; each session was 40 minutes. Results: Cohen’s effect coefficient percent and independent samples t-test were used to analyze the data collected in pre-test and post-test. Significant differences were shown in aerobic power, feet explosive power, fatigue index, fatigue percentage, maximum anaerobic power, mean anaerobic power, and running sprint (P≤0/05). There were no significant differences in maximum running sprint; total time repeated running sprint ability, minimum anaerobic power, agility, and distance running (P≤0/05). Conclusion: The results of this study have suggested that the basketball movement specific training circuit should be used to improve aerobic power, fatigue index, and fatigue percentage. Also, classical training has suggested in order improving feet explosive power, maximum anaerobic power, means anaerobic power, and running sprint.

Pull-up and modified pull-up tests are frequently used for shoulder muscles
endurance evaluation by physical educators. Despite of using these tests, the
difference of muscle activation pattern in pull-up and modified pull-up tests has
not been documented clearly. However, the role of some important muscles
such as anterior deltoid, posterior deltoid, trapezius and latissimus dorsi have
not yet examined during these tests. This study aimed to determine effects of
pull-up and modified pull-up tests on the EMGs recordings from selected
muscles including anterior deltoid, posterior deltoid, biceps, triceps, pectoralis
major, trapezius and latissimus dorsi. Ten able-bodied males (age: 25.32 ±
3.95 yrs; weight: 72.31 ± 7.24 kg) who were able to do at least 5 pull-ups were
selected to participate in the study. Surface electromyographic data were
recorded from selected muscles using De Luca and Basmajian’s method.
ANOVA with repeated measures was employed for comparison of
electromyographic activity in the selected muscles during pull-up and modified
pull-up tests (p  0.05). The results revealed that in modified pull-up test
anterior deltoid, posterior deltoid and trapezius muscles activation were
significantly higher in comparison with pull-up test, while the EMG activity of
biceps, triceps and pectoralis major was significantly higher in pull-up test.

Introduction: Whole Body Vibration (WBV) as a new method and supplement for neuromuscular training, cause mechanical stimulation in this system. Propose: The aim of present study was to determine the effect of Whole Body Vibration training (WBVT) on some factors of the physical fitness, growth hormone and IGF-1 concentration in trained girl students. Materials and methods: twenty female of physical education students with a mean and standard deviation of age (21.75 ± 2.2 Yr.), weight (54.25 ± 7.28 kg) and BMI (20.1± 2.44 kg/m2) were selected and randomly divided into two groups: experimental (n=10) and control (n=10). WBVT for 10 days with frequencies 30 Hz and amplitude of 10 mm in six different body positions were performed. Blood samples were collected 24 hours before and after WBVT. Data were analyzed by dependent t test and paired t test. Results: The statistical analysis showed, WBVT lead to significant increase of strength, speed, power, growth hormone and IGF-1 concentrations in experimental group (P<0.05), while agility in this group was not significantly changed (P>0.05). Conclusion: WBV training program can be used as modern training methods and supplements along with other training methods to improve the levels of anabolic hormones and physical fitness factors.

The purpose of this study was to investigate the relationship between sprint performance of front-crawl swimming and muscle fascicle length in 23 male young swimmers. The sample was divided into two groups by 25-m sprint front-crawl swimming performance: 14.6-15.7 s (S1, n=11) and 15.8-17 s (S2, n=12). Muscle thickness and pennation angle and fascicle length of the Biceps Brachii (only muscle thickness) and Triceps Brachii and Vastus Lateralis and Gastrocnemius Medialis and Lateralis muscles were measured by B-mode ultrasonography. S1 had a significantly greater Vastus Lateralis, Gastrocnemius Lateralis, and Triceps Brachii muscle thickness. Pennation angle only in Triceps Brachii was significantly smaller in S1. S1 in Vastus Lateralis, Gastrocnemius Lateralis, and Triceps Brachii muscles had significantly absolute longer fascicle length and in Vastus Lateralis and Triceps Brachii muscles, had relatively (relative to limb length) longer fascicle length. There was a significant relationship between sprint performance of front-crawl and absolute and relative fascicle length in Vastus Lateralis (absolute: r = -0.49, relative: r = -0.43) and Gastrocnemius Lateralis (absolute: r = -0.47, relative: r = -0.42). It is concluded that muscle fascicle length is one of the effective factors on the sprint front-crawl swimming in young swimmers.