Journal of Sport Sciences and Health Research
Volume:1 Issue: 1, 2009

The purpose of this study was to examine cardiovascular and respiratory changes in students carrying backpacks. 15 male students (age: 12.5±0.5 years old; height: 164.7±1.8 cm; and weight: 55±1.6 kg) volunteered to participate in this study. All subjects randomly carried backpacks of 0%, 8%, 10.5% and 13% of their own body weight in different days on treadmill at 3.9 km/h for 15 minutes. Heart rate (HR), pulmonary ventilation (VE) and frequency respiration (FR) of the subjects were measured by Gas Analyzer System and SBP and DBP were measured by a digital blood pressure meter in 3 positions: test, exercise (15th minute) and recovery (3 minutes after walking). The statistical analysis of data indicated that SBP, DBP and VE in 10.5% and 13% load conditions were significantly higher than in 0% and 8% load conditions (P=0.000). Also, 10.5% and 13% load conditions were significantly higher 3 minutes after walking when compared to the rest level (P=0.000). There were no significant differences between 0% and 8% load conditions in both during and 3 minutes after walking conditions. HR and FR of subjects showed no significant difference during and after carrying different loads. According to the results of the present study, carrying backpacks equal to 8% of body weight does not create any significant changes in cardio-respiratory parameters of students, thus it can be recommended as an optimal weight of backpack for students.

The aim of this study was to assess whether proprioceptive information of trunk muscles as a reference frame plays a role in determining directions. Eleven young healthy right-handed male subjects (age: 23.78? 0.78 years, height: 169.7?5.7 cm, and mass: 62.8? 6.8 kg, BMI: 22.34? 1.7 kg/m2) volunteered to participate in this study. Unilateral trunk muscle vibration was applied either from the beginning or the middle of a seven-step task with their eyes open (OE) or blindfolded. The deviation from the walking path was determined as the distance of the seventh footprint from the first one along the mediolateral axis. Foot angles and stride lengths were calculated for all footprints. All deviations from the straight path were measured by footprint deviation from the reference line on the ground. Two-way repeated measure ANOVA (two vision conditions and three vibration conditions) was used to test the significant difference in distance parameter. Three-way repeated measure ANOVA (vision and vibration conditions and angle of footprint) was used to determine the difference between the mean angle of foot deviation from the reference line and stride length within and in the middle of the three vibration conditions and two vision conditions. The results showed that vibration produced a clear-cut deviation from the straight direction when delivered in the middle of blindfolded locomotion (P=0.0.1). The deviation was much smaller with OE (P=0.06). A mild deviation was obtained in blindfolded condition when vibration started at the beginning of locomotion (P=0.77). Trunk proprioception plays a major role in defining locomotor trajectory.

The risk of injury in soccer is considerable, but few studies compared soccer injury incidence at European and Asian tournaments. The purpose of this study was to compare the incidences and patterns of soccer injury at Asian Cup 2007 and European Cup 2008. Thirty one matches from Asian Cup 2007 and 31 matches from European Cup 2008 were analyzed by video analysis system. Injury incidence at Asian Cup was significantly higher than European Cup (Z=5.75, P>0.05), (109.7 vs. 39.6 injuries per 1000 hours). Results of this study showed no significant differences in time lags between the two tournaments (X2 = 4.41, P>0.05). Also, there was a significant difference in different positions between the two tournaments (X2 – 16.88, P<0.05); mid fielders (28.9%) in European Cup and goalkeepers (22.4%) in Asian Cup were more injured than other players. No significant difference was found in player's injured part of body between the two tournaments (X2=12.96, P>0.05), but the most common injury for Asian players was the lower leg (20.8%) and for European players was the head (24.4%). This study showed that injury incidence in Asian Cup was higher than European Cup and factors such as player's position can affect player's injuries in Asian and European tournaments.

The aim of the present study was to determine the most effective stretching method to restore hamstring flexibility in a minimum period in male soccer player. Forty four soccer players (age range: 20-29 years) were selected by simple non-probability sampling. Subjects were randomly assigned to four groups, (11 members each group): (1) static stretching group, (2) hold-relax stretching group (HR), (3) stretching after post isometric relaxation (PIR), and (4) stretching based on reciprocal inhibition principle (RI). Stretching was carried out for six weeks, 6 sessions per week, and 2 minutes each session. Active and passive knee extension and passive hip flexion (degrees) were measured by a goniometer. The obtained data were analyzed by one-way ANOVA and repeated measures. Active knee extension increased from 155.1?2.5 to 170.9?3.4 in static stretch group, from 157.5? 4.5 to 174.9? 2.9 in HR group, from 155.2? 4.5 to 171? 2.9 in PIR group, from 156.4? 2.5 to 170.6? 3.9 in RI group (P<0.0001). Passive knee extension increased from 157.9? 5.2 to 173.8? 4.9 in static stretch group, from 160.9? 3.2 to 176.3? 4.1 in HR group, from 157.9? 1.2 to 173.9? 3.2 in PIR group, from 157.6? 5.1 to 173.5? 4.2 in RI group (P<0.0001). Passive hip flexion increased from 64.8? 4.3 to 77.4? 6.3 in static stretch group, from 65.8? 3.3 to 80.5? 1.1 in HR group, from 67.1? 2.9 to 79.5? 5.2 in PIR group, from 66.8? 3.2 to 78.3? 4.6 in RI group (P<0.0001). The results showed that no specific method which improves hamstring flexibility in soccer players was superior to others.

The aim of the present study was to investigate three important mal-alignments (pronation, tibial torsion and Q angle) as risk factors in ACL tear in professional female athletes. Twenty ACL – injured females (age 24.90? 5.75 years, height 167.05? 6.58 cm, mass 60.88? 5.58 and athletic experiences 7.70? 4.41 years) and 20 uninjured females (age 24.80? 5.59 years, height 166.15? 6.39 cm, mass 60.20? 6.08 and athletic experience 7.00? 3.69 years who were the injured female's counterparts based on their age, sport field and injured limb) participated in this study. Navicular drop, tibial torsion and Q angle were measured in both limbs. Mechanism of injury was non-contact in about 90% of cases. In 17 cases (58%), a medial meniscus injury was reported. The findings showed a significant difference in pronation and tibial torsion between groups (P<0.05). These was no significant difference in Q angle between groups (P<0.05). Also there was no significant difference in lower extremity alignment between injured and uninjured limbs of ACL-injured group. Therefore, it is suggested that the biomechanical risk factors are identified and athletes with hyper-pronation and internal tibial torsion are screened as they may be predisposed to ACL injury. It is also necessary for coaches to apply corrective and prevention programs.

The purpose of this research was to study the effect of caffeine supplement ingestion following a graded interval exercise on ferry fatty acid (FFA), lactate (LA), epinephrine and nor-epinephrine in paraplegic disable individuals. Seven paraplegic disabled individuals participated in this study (age 38.9? 2.13 years old, fat percent: 26.53? 6.89, weight: 82.33? 4.12). Subjects participated in two interval wheelchair trainings with a one-week interval. At first, subjects took part in an interval exercise without the ingestion of caffeine supplement (6 mg per kg) one hour before the exercise (P<0.05). The data of exercise without caffeine ingestion revealed no significant changes in blood FFA, epinephrine and nor-epinephrine but blood lactate significantly increased. After the ingestion of caffeine supplement data showed a significant increase in blood FFA, LA, epinephrine and no significant change in nor-epinephrine. With respect to these findings, one can conclude that caffeine supplement can affect lipid metabolism. Therefore, caffeine can increase body metabolism and can decrease body fat percent of paraplegic disable individuals.

The aim of this research was to study the relationship between habituated posture when resting and postural deformities of upper trunk. The statistical population of this study consisted of all female students in dormitories of Shiraz state universities (Shiraz University, Industrial University and University of Medical Sciences) (N = 4500 people). 402 students were selected randomly. A researcher-made questionnaire was used to study the way of resting and spinal column conditions (validity 83%). It was distributed among students and then their body postures were studied by New York test, checkered sheet and plumb line. To measure the angles of thoracic and lumbar curve, the flexible ruler was used. Its validity was reported as 78% when compared to radiography technique. The data were analyzed by statistical software SPSS.10 and Spearman test (??0.05). The results showed no significant relationship between sleeping on back with stretched legs and lumbar lordosis and also between sleeping on back and raising hands with scoliosis and uneven shoulder. Also there was no significant relationship between side sleeping and bending legs and head into stomach to kyphosis and between side sleeping and the upper knee on the ground (with turning pelvis) to scoliosis. In this research, a significant relationship (r=0.39, P=0.037) was found between side sleeping while upper trunk was located farther than lower extremities and lumbar lordosis; also between sleeping on stomach and lumbar lordosis. The results showed no significant relationship between sleeping on stomach and neck lordosis, but there was a significant relationship between sleeping on stomach and kyphosis. The findings of this research did not show any significant relationship between the weight of the subjects and the sleeping condition and spinal column disorders; however, there was a significant relationship between the height of the subjects and side sleeping and upper knee on the ground. According to the results, there was a significant relationship between some resting conditions and postural deformities of upper trunk. It seemed that the effect of resting condition on deformities of upper trunk was not serious but it is necessary to make the students aware and to correct incorrect resting habits.

Due to the high incidence of ACL tearing in female athletes and the importance of proprioception and knee dynamic stability, functional assessment of knee joint proprioceptin is necessary. Therefore, the aim of this study was to compare two functional movements in knee joint proprioceptin assessment in healthy female athletes. 16 healthy female athletes volunteered to participate in this study. Knee joint position sense was evaluated by the reproduction of the target angle in weight-bearing position and two different tasks of movement (from full extension to 30° flexion and from semi squat (60° flexion) to 30° flexion). Absolute angular error was considered as a dependent variable. Data were analyzed by paired T-test. Results indicated no significant difference between two tasks of limb movement (P>0.05). Therefore, the results of this study suggested that the combination of mechanoreceptors is stimulated equally in both tasks.