Vahideh Teimouri Gholeh Zo, Fatemeh Alirezaei Noghondar, Hamid Reza Taheri,
Volume 18, Issue 20 (11-2020)
Abstract
The purpose of the present study was to investigate the effect of dual task training including balance sit-to-stand and cognitive exercises on postural control of sit to stand of elderly women with a history of falling. 15 elderly women were randomly divided into control (n=7) and experimental (n=8) groups. Participants implemented training protocol for four weeks in both experimental (balance and cognitive exercises) and control groups (balance sit-to-stand exercises). Before and after the training protocol, Berg Balance Scale and time of up and go tests were applied. Besides, in order to measure amplitude and speed of postural sway in the anteroposterior and medio-lateral direction in different stages of sit to stand movement in dual task condition, a force plate with a frequency of 100 Hz was used in pre-test and post-test. For data analysis, paired and independent t-test, nonparametric Wilcoxon and Mann Whitney u-tests were used with a significance level of P≤0.05. The results showed that there was a significant difference in the BERG test and significant reduction of the amplitude and speed of center of pressure in the antero-posterior and medio-lateral directions in the experimental group compared to the control group from pre-test to post-test (P≤0.05). Due to results, balance exercises by dual task method improved control functional balance and reduced postural sway and consequently improved sit to stand postural control in dual task condition and therefore can reduce more effectively the risk of falling in elder people.
Karar Khajeh Nemat, Heydar Sadeghi, Ismaeil Ebrahimi Takamjani, Raghad Memar,
Volume 18, Issue 20 (11-2020)
Abstract
Proprioception is essential for joint function and through which individual can detect body parts movement in space. Aim of present study is to investigate effect of balance training on unstable platform with tilting, translation and combined motion on knee joint position sense in active young males. 39 healthy active male divided in to three training and control (n=9) groups. Training on unstable platform with tilting motion group (n=10), Training on unstable platform with translating motion group (n=10) and combined training group (n=10) performed exercises program for 8 weeks, three times a week. Errors in repositioning of knee joint in 30, 45 and 60⁰ angles (active and passive) was measured by Biodex system 3, before and after training period. Data was analysed by using one-way ANOVA test (P≤0/05). Although after 8 weeks, active and passive errors in repositioning of knee joint in mentioned angles decreased in training groups but this difference was not significant (P≤0/05). Balance training on unstable platform alone cannot have a big effect on knee joint position sense in active young male.
Mr Hamid Mahmodi, Dr Hamid Rajabi, Mr Mohsen Bapiran, Dr Pezhman Motamedi,
Volume 19, Issue 21 (9-2021)
Abstract
The purpose of this study was to compare the effect of plyometric training pre and post maturation period with soccer training on electromyographical index and soccer players performance. 30 students of soccer player's pre maturation period (weight 32.38±6.59 kg, age 10.35±0.59 years, and height 141±0.06cm) and post maturation period (weight 43.79±10.96 kg, age 15.43±0.72 years, and height 156.84±0.09 cm) were selected. Subjects in the experimental group were 15 students before and after maturity period. To evaluate the age of the indices such as height, age, dental and bone age (radiographic method) was used. Then, for homogeneous groups of index of biological age radiography was used by radiologists. Before and after 4 weeks of training,, functional tests of two 20 meter speed, agility, vertical jump and also Amplitude for vastus lateralis muscle Were taken. The result by using Paired t-test showed that in pre maturation group in the vertical jump, agility and 20 meters there was a significant difference (P=0.002,P=0.006,P=0.001) and the other variables there was no significant difference. In variations between the groups, independent t-test showed that only significant differences was found in the test 20 meter speed (P = 0.007) and in the other variables not significantly different. The results showed that plyometric training in the Pre maturation group compared to post maturation group were more effect and these results can help in the design training for premature age groups
Mr Iman Rouzbeh, Dr Amirhossein Barati, Dr Hooman Minoonejad,
Volume 19, Issue 21 (9-2021)
Abstract
As Squat is a popular exercise for support of lower extremity muscles in order to injury prevention this study has been hold to comprise the electromyography of vastus medialis and vastus lateralis muscles in three Squat techniques of man soccer players. 15 soccer players, aged 18-25 years old, who had regular exercise more than two years did open, closed and lung Squats exercise while electromyography of vastus medialis and vastus lateralis muscles were recorded. Data analyzed by using dependent and independent T test and repeated measure ANOVA. There was not significant difference of vastus medialis and vastus lateralis muscles’ electromyography during getting up, going down phases and also for different squat techniques. The vastus lateralis muscle show more activity in all conditions. Though, it is recommended that vastus medialis has bold role for controlling of squat exercise, reduction of Q angle and participants’ knee varus in this study can be the reason of antithesis.
, , Elham Shirzad,
Volume 19, Issue 21 (9-2021)
Abstract
Despite the importance of talent for sports, but it has yet received little attention. The purpose of this study was to present a pattern design for talent identification in karate based on artificial intelligence algorithms. Subjects divided to adolescent elite karate athletes (n = 19) and non-karate athletes adolescent (n=20) by convenience sampling. Besed on previous literature, we selected and measured biomechanical and anthropometric variables. The normal distribution of all data was analyzed using Shapiro-Wilk test. Principal component Analysis (PCA) was performed to reduce the number of variables and identify the most important anthropometric and biomechanical variables. Then, for modeling, the neural network algorithm was used with three input layer (10 neurons), middle (7 neurons) and output (2 neurons). The results showed the most important anthropometric variables of adolescent elite karate athletes were thoracic subcutaneous fat, height, jump, static balance, grip strength, chest circumference, ankle circumference, abdominal subcutaneous fat and apparent length leg respectively. Also, percentage of correct classification and sensitive of data was high and 87% and 85% respectively. According to the results of this study, this method can be used for talent karate athletes along with other methods.
Azadeh Doroodgar, Khalil Khayambashi, Shahram Lenjannejadian, Ghasem Yadegarfar,
Volume 19, Issue 21 (9-2021)
Abstract
Hamstrings (Hams) to Quadriceps (Quadr) strength ratio is known as a risk factor for Anterior Cruciate Ligament (ACL) injury and affects by knee and hip flexion angles. Gluteus Maximus (Gmax) muscle acts as a synergist for Hams in hip extension in a closed kinetic chain. The aim of this study was to investigate the effect of Gmax strengthening exercises on the kinetic and kinematic risk factors of ACL injury when single-leg landing from a jump. 25 volunteer women aged 18-30 years were assigned into control (n =13) and experimental (n =12) groups. Maximum isometric strength of Gmax, hip and knee joint angles and ground reaction force (GRF) was measured at landing, by dynamometer, 2D imaging and foot scan respectively,. After 8 weeks of 3 sessions of Gmax resistance training, Following the significant within-subject difference for GRF (F=5.245, P=0.032) by using Two-way mixed model ANOVA, Pre and post-test Differences were significant with 16.63% decrease (P= 0.038, t=2.354). Differences between pre and post-test peak force, time to peak, mean joint angles, impact and load rate were not significant (α = 0.05). According to a 4.55% and 3.47% increase in Gmax strength and time to peak force, and considering the fact that at the beginning of landing, the mechanical advantage of Hams is lower than that of Gmax, the risk of ACL injury could be reduced by reducing GRF following an increase in the Gmax strength.
Dr. Leila Ghazaleh, Mis Fahimeh Bakhshizadeh, Dr. Rana Fayazmilani,
Volume 19, Issue 21 (9-2021)
Abstract
It is necessary to examine the changes of muscle co-contraction in different percent of fatigue-induced force reduction. The present study aims to investigate the effect of fatigue-induced force reduction of knee extension on muscle co-contraction. Ten healthy and active women aged 26.10±2.99 years performed fatigue protocol including 5 seconds of maximal voluntary isometric contraction (MVIC) of the knee extension and a 5-second rest. Muscle co-contraction was calculated for each subject in the repetitions in which the MVIC force was reduced by 10, 20, 30, 40 and 50% as compared to the pre-fatigue MVIC force. Knee extension force and muscle activity measured by Isokinetic and electromyography apparatus, respectively. The difference between co-contraction of vastus lateralis and medialis in different percentages of force reduction was not statistically significant. The co-contraction of rectus femoris and biceps femoris increased by 40 and 50% of force reduction compared to pre-fatigue co-contraction (P<0.01). Co-contraction of biceps femoris and vastus lateralis increased by 20, 30, and 40%, as well as co-contraction of biceps femoris and vastus medialis increased 40% of the force reduction, compared to pre-fatigue co-contraction (P <0.05). The results, overall, showed that the change of co-contraction during fatigue is influenced by the selected muscle and the rate of force reduction. This finding can help researchers decide how neuromuscular fatigue effects on muscle co-contraction
Mr Mohamadreza Hatefi, Dr Ramin Balochi, Dr Farideh Babakhani,
Volume 19, Issue 21 (9-2021)
Abstract
The purpose of this study was to investigate the effect of different hip joint postures on electromyographic activity of selected lower limb muscles during squat's movement. Electromyographic activity of selected lower limb muscles of 15 healthy male students was recorded while performing a squat with neutral, 15°, 30°, 45° external and internal rotation of the hip. Friedman's nonparametric test was used to compare muscle activation at different angles of the hip rotation and the Wilcoxon test was used to determine within-group differences. The results of this study showed no significant difference in the activity of Vastus medialis (p = 0.052), Vastus lateralis (p = 0.102) and tensor fasciae lata (p = 0.193) in squat between different hip joint angles, but Significant differences were observed in gluteus medius muscle activation (p = 0.001) and biceps femoris (p = 0.015) in squat between different hip joint angles. Also, the results of this study showed that gluteus medius to tensor fascia lata activation ratio was significant in squat between different hip joint angles. squat with the external hip angles can be considered as an effective method to increase gluteus medius activation and gluteus medius to the tensor fasciae latae activation ratio. On the other hand, 45 ° external and 30 ° internal hip angles can be considered as an effective method to increase the biceps femoris activation.
Mr Amir Hossein Tavari, Dr Mohammad Hadi Honarvar, Dr Mostafa Hajlotfalian,
Volume 19, Issue 21 (9-2021)
Abstract
In recent years, efforts have been made to use non-invasive methods to achieve these angles. The aim of this study was to investigate the capabilities and reliability of a non-invasive system based on surface data mining using infrared depth cameras. To do this, you must first use a number of mathematical relations to create a cloud of points of the surface and to extract the desired deviations by geometric analysis of the map and surface topography. In this study, after extraction of cloud of points, the gossip method based on the second surface derivative was used to identify anatomical landmarks. Based on this, the body surface area was divided into a number of convexity, convection and parabolic. Then, by mathematical analysis of the surface topography map, the angles of a number of backward anomalies were estimated. To test the repeatability of this method, intra class correlation coefficient and minimum detectable changes were used to evaluate the relative and absolute reliability. The results of this study showed that it is possible to identify landmarks using the second derivative method with appropriate accuracy. The results of the reliability survey also showed acceptable and high values for the studied angles. Thus, it can be said that the use of this method has a good introverted reliability and can be a good alternative to radiography in continuous evaluations.
Marjan Asadi, Heydar Sadeghi,
Volume 19, Issue 21 (9-2021)
Abstract
Knowledge of the relationship between performance and range of motion, helping to design training programs, comply of individual with the needs of children is, therefore, The aim of research the relationship between some of the lower extremity range of motion and biomechanical parameters of the boys was performed. Hundred students in this study were randomly selected. After measuring the range of motion of lower extremity, test speed, power, balance and agility of the subjects were recorded. By descriptive statistics to determine the mean and standard deviation of the method of multiple correlations to assess the relationship between the selected range of motion and biomechanical parameters of subjects were used. Hip flexion by speed, hip abduction and knee flexion by balance and hip flexion, hyper adduction and ankle dorsi flexion significant positive correlation by the agility, the rate of hip and knee flexion by power a significant negative correlation and with other lower extremity range motion parameters showed a significant positive association. According to the research findings, seem to be characteristics of the children lower extremity range of motion and identify performance indicators for various athletic field, can be used.
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.
, , , ,
Volume 19, Issue 22 (12-2021)
Abstract
Aim: Neuropathy control and management is an objective in therapeutic exercises prescribed for patients with Type 2 diabetic peripheral neuropathy. We examined the effects of 12-week integrated exercises (IE) on glycemic control and peripheral sensation criteria in patients with diabetic neuropathy. Methods: Based on scores of MNSI, we assigned 40 patients into two equal paired random groups (control vs. IE). Pre and post-tests were administered before and after three months of intervention for 3 sessions per week with a time of 60 minutes in the first week and gradually increased with the duration and volume of training to 90 minutes in the final session.
Results: Repeated measures ANOVA showed no significant interaction between FBS of the groups (P = .26), but significant interactions were observed between the levels of 2 hrs pp G , 4 pm G, HbA1c, Diapason, Monofilament, and Thermofeel in favor of the IE group (P <.05). Conclusion: At the beginning of the IE, we used massage and foam roller to release pain, and improve blood circulation as well as sensation in the neuropathic areas. This may have helped the patients perform the aerobic and resistance exercises more easily Therefore, better glycemic control and peripheral sensation was achieved. Verification of the long-term effects of this training strategy requires further study.
Setare Beyhaghi, Neda Khaledi, Doctor Hossein Askari,
Volume 20, Issue 23 (9-2022)
Abstract
Recent studies indicate that environment can modify skeletal muscle gene expression and transcriptional factors in offspring genes. Therefore, exercising can lead to changes in the gene expression of the future generations. One of the important metabolic factors is PDK4, which is known as the main factor in Pyruvate Dehydrogenase Complex (PDC). This study examined the effects of maternal exercise on PDK4 expression in slow and fast twitch (soleus and EDL) muscles of male offspring. Twenty Sprague-Dawley rats were divided to three training groups: before pregnancy (TBP), during pregnancy (TDP) and before and during pregnancy (TBDP) and pregnancy without training (control) group. Training groups were running on a treadmill for four, three and seven weeks, respectively. Two months after the birth of the offspring, 6 male rats were chosen randomly from the offspring of each group. The samples were anesthetized using Ketamine (90 mg/kg) and Xylazine (10 mg/kg) and their soleus and EDL muscles were removed immediately for examine. Gene expression of offspring muscles were analyzed using real-time RT-PCR. Fisher test were used to analyze the difference between the training and the control group. PDK4 expression of offspring were significantly increased in all groups except for EDL muscle of the TBP group. According to the results, it seems likely maternal exercise training can affect the metabolic regulation in the offspring by increasing the expression of some metabolic genes.
Homa Sheikhani Shahin , Davood Mehrabani , Seifollah Dehghani Nazhvani, Hamid Rajabi, Manijeh Norouzian ,
Volume 20, Issue 23 (9-2022)
Abstract
The aim of this study was to the effect of aquatic activity and alogenic bone marrow derived mesenchymal stem cells fortified with Platelet-Rich Plasma in treatment of Achilles tendon in rat. 74 Sprague-Dawley rats were selected and tendon injury was formed in 69 of them. Subsequently, these rats were randomly divided into 8 groups and 5 rats which were without any injuries were chosen as the control group. 72 hours after the surgery, isolated cells from bone marrow and PRP were injected to the groups via catheters. The experimental groups had aquatic activity for 8 weeks. At the end of the eighth week, the Achilles tendon was separated and H&E and Mason Trichrome were used for special staining to assess the tendon healing. The results show there is a significant difference between the studied groups on the Achilles tendon healing. Also, results from histopathological examination indicated that there is a significant difference between the studied groups on the number of fibroblasts, collagen deposition, cellularity and tendon diameter. It could be generally concluded that, using these treatment methods could help with the tendon healing through bounding with target cells membrane receptors such as fibroblasts, mesenchymal stem cells and endothelial, which leads to activation of a series of intracellular proteins and as a result of their activities some reactions happen that lead into formation of matrix and collagen synthesis.
, , , ,
Volume 20, Issue 23 (9-2022)
Abstract
Background and Aim: Given the widespread trade in some sports, a misjudging decision can not only have huge financial consequences for competitors, but also affect the event itself. The overall purpose of this study was to determine the role of information technology and perceived organizational support on the performance of the referees of the 2018 FIFA World Cup in Russia: to investigate the mediating role of job satisfaction and self-efficacy. Methods: This is a descriptive research, correlation model, based on structural equation modeling, and its type. The statistical population of the study consisted of all referees and assistant referees present at the 2018 FIFA World Cup in Russia, of which 111 referees were 35 middle referees, 63 assistant referees and 13 video assistant referees. Results: The results showed that information technology, perceived organizational support and self-interest have a significant positive effect on the performance of the referees of the 2018 FIFA World Cup in Russia. Job satisfaction does not have a significant effect on the performance of the referees of the 2018 FIFA World Cup in Russia. Conclusion: Information technology is an effective and facilitating factor in arbitrators' decisions, so it is suggested to provide technological infrastructure in order to improve the instant decisions of arbitrators on a larger scale.
