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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.
Mr Amin Mardazad, Dr Amirali Jafarnezhadgero, Mr Sajad Avazzadeh,
Volume 0, Issue 0 (11-2019)
Abstract
Warm up method can be considered as a strategy for improving athlete’s performance. The purpose of this study was to provide a useful data as warm up to improve the performance of athletes, including volleyball players by increasing their jump height. In the present review study by using the following keywords included Post-Activation Potentiation, Squat Jump, Warm-up, Volleyball, Jump Height, Force Plate, and electromyography the search process was done in Google scholar, the Pubmed databases and Scientific Information database and Google scholar. In the identification stage, 387 English and 15 Persian articles related to the mentioned keywords were found. Finally, the number of English articles reached 42 and the number of Persian articles reached 6. The results of this review-descriptive study showed in the final stages of Post-Activation Potentiation warm-up, performing high intensity squats by creating acute changes in neuromuscular system can increase in jump height of athletes including volleyball players in match and practice.
Mr Amir Reza Sedighi, Dr Mehrdad Anbarian,
Volume 18, Issue 20 (11-2020)
Abstract
The purpose of this study was to determine the immediate effect of three types of shoe insoles, on electromyography activity of selected lower extremity muscles during running on treadmill. The electromyography activity of the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior and gastrocnemius lateralis muscles of 14 male athletes were recorded in non-insole, wearing soft, semi-rigid and rigid insoles conditions during running on treadmill. Electromyography activity of the rectus femoris muscle in the loading phase was lower in soft insole condition than other conditions. In the pre-swing/early swing phase, there was difference of the rectus femoris muscle activity in the soft/non-insole and soft/semi-rigid conditions. In this phase, the biceps femoris muscle had different activity in the semi-stiff/non-insole and semi-rigid/rigid conditions. In the mid-swing phase, there was a difference in the activity of the rectus femoris and the tibialis anterior muscles in the non-insole/semi-rigid condition, and the gastrocnemius lateralis muscle in the non-insole condition with other conditions. There was difference also for biceps femoris muscle activity in the semi-rigid/non-insole condition in the pre-activation phase. The vastus lateralis and gastrocnemius lateralis muscles activity in the soft insole condition was lower than that of the semi-rigid condition. It seems that the intensity and contraction pattern of the muscles change while using different shoe insoles with different variety of stiffness during running. It could be useful in choosing a shoe insole with a suitable stiffness material level for clinical and training purposes.
Dr Shirin Yazdani, Prof Nader Farahpour,
Volume 19, Issue 21 (9-2021)
Abstract
Background and Objective: although it is documented that the spine and hip alignments alter in scoliosis subjects, but the effect of these changes on the lower extremities’ biomechanics have not been well understood yet. So, the aim of this study was to compare hip, knee and ankle joint’s power generation and absorption during gait in patients with adolescent idiopathic scoliosis (AIS) and healthy controls. Methods: Using motion analysis system with 4 Vicon-460 cameras and two Kistler force plates, the kinematics and kinetics of gait was assessed in twenty girls with AIS and 20 matched healthy controls, then the power of the right and left hip, knee and ankle joints in sagittal plane was calculated. Data was analyzed using ANOVA statistical method with significance level of α<0.05. Results: Results showed that in scoliosis group, the peak power absorption of the right knee was significantly 12.5% smaller than that in control group (p=0.01). But, peak power generation and absorption of the hip and ankle joints in both right and left limbs were not statistically differed between the two groups (p>0.05). Conclusion: scoliosis is associated with the smaller power absorption of the knee joint at convex side. This might be linked with unilateral alterations of the joints' moment, joint forces, and the related muscle activity which might impose asymmetrical force to the hip and cause curve progression.
Mahboubeh Alemzadeh, Seyed Abdolali Hosseini, Mehrdad Anbarian, Safoura Ghasemi,
Volume 19, Issue 22 (12-2021)
Abstract
Nowadays, light and minimal shoes have been used by athletes in various types of sports activities in order to be in a position close to barefoot position. But its effect on the electrical activity of the shank muscles is not well understood. Therefore, the aim of this study was to investigate the electrical activity of selected shank muscles when using minimalist shoes, normal shoes and barefoot during single-leg landing. For this purpose, 15 healthy boys with a mean age of 23.53± 2.64 years who had no history of any abnormalities participated in this study. Electromyographic variables of tibialis anterior, peroneus longus, peroneus brevis, gastrocnemius medialis, gastrocnemius lateralis and soleus muscles of subjects' superior legs were examined in two phases; pre-activity and eccentric. Analysis of Variance (ANOVA) with repeated measures tests were used for data analysis. The significance level was set at α=0.05. The results showed that in both phases, the activity of selected muscles in the shank of individuals during the one-legged landing movement in the barefoot position was more than the minimalist shoes and when using the minimalist shoes was more than normal shoes (P<0.05); Since minimalist shoes have been shown to have moderate muscle activation patterns, between barefoot and casual shoes, it is recommended to use it to prevent sports injuries and also to strengthen the shank and leg muscles in environments where it is not possible to move barefoot.
Mr Mojtaba Sadeghi, Dr Hamid Rajabi, Dr Farzad Nazem,
Volume 21, Issue 25 (9-2023)
Abstract
The purpose of this study was determine the effect of upper body plyometric training on anaerobic power and record of 25 meters front crawl performance in 10 years old swimmer boys. 16 swimmer boys chosen voluntarily (The mean age was 9.9 ± 0.7 years ، weight 45.9 ±9 kg , Height 149.8 ± 5 cm، BMI is 19.20 ± 3 Kg / m 2 ) And Subjects divided into two groups of training (n=8) and control(n=8).Before and after the implementation of the protocol investigate test 25 meters front crawl performance at the distance 10, 20 and 25 metrs and the number of hand strocke to check the performance of the swimming also anaerobic hand wingiting test function was evaluated. To analyze data, used the covariance test.The results showed six weeks upper body plyometric training Performance Indicators an hands Front crawl Including Peak power increased Significantly (18%) but the average power increase (7%) was not significant (p>0.05). Also, Swimming performance at of 10 meters) 8% (,10 to 20)6%( and 25 meters distance( 3/80%) growth in compare to control group that was significant(p <0.05) As well as in the number of hand strocke, Plyometric training group although had growth in swim 10 meters (11%), 10-20 meters (7.5%) and in 25 meters distance (5.33%) but the isnt significance (p>0.05). results indicate that six week upper body plyometric traning to an increase and improvement in the measured parameters, and can be used as a complementary training method in young swimmers.
Zahra Ghahremani, Hassan Daneshmandi, Mehrdad Anbarian,
Volume 21, Issue 26 (12-2023)
Abstract
The purpose of this study was to assess the acute effect of warm-up protocols (general and post-activation potentiation) on vertical jump performance and jump-landing technique in female handball players with trunk dysfunction. Twelve trained female handball players with trunk dysfunction participated voluntarily in this study. Subjects randomly performed three different warm-up protocols on separate days: 1- general warm-up protocol, 2- general warm-up with 2 repetitions of dynamic half-squat at %90 of one repetition maximum, 3- general warm-up with 2 repetitions of static half-squat at %90 of one repetition maximum. In the fifth minutes of recovery period after 3 protocols, subjects performed vertical jump and the Landing Error Scoring System tests, and Landing Error Scoring System scores, valgus and flexion angles, and vertical jump height was assessed. ANOVA with repeated measures was used for statistical data analysis. The jump height increased significantly after performing the second and third protocols related to general warm-up (p=0.039, p=0.047 respectively), but there weren’t a significant difference in Landing Error Scoring System score, valgus and flexion angles for three protocols. It seems that the special warm-up method by post-activation potentiation can improve vertical jump performance without influencing Anterior cruciate ligament injury risk.
Maliheh Ardakanizadeh, Alireza Rahimi, Leila Vesaliakbarpour,
Volume 22, Issue 28 (12-2024)
Abstract
It seems that aerobic exercise in water is more effective in promoting motor fitness factors due to its greater resistance force compared to the dry environment. Accordingly, the aim of this study was to compare the effect of aerobic exercise in water and land on the physical fitness of inactive girls.
Thirty non-athletic girls were randomly divided into two groups water and Land (n=15), and performed aerobic activity for six weeks (3 sessions/week) with 60-70% of maximum heart rate. Before and after aerobic activity, was calculated their explosive power using the vertical jump (Sargent), agility (4×9test), reaction (reaction time test), and the balance (static balance test). For compare pre- and post-test, and to compare post-test results in water and land, One-way ANOVA (p≤0.05).
After aerobic activity (water and land) compared to before, significant improvement was found in the values of explosive power (p=0.001), agility (p=0.001) and static balance (p=0.003), while the comparison of training in water and land did not show a significant difference (p>0.05).
It seems that aerobic activity (water and land) can affect explosive power, agility and static balance, but no effect on reaction, also there is no difference between the two environments.
