نشریه پژوهش در طب ورزشی و فناوری
پیاپی 23 (بهار و تابستان 1401)

The purpose of present study was to examine the effects of short time static and dynamic stretching of muscles on kinematics variability of lower extremity in healthy active males during cycling. 15 physical education and sport sciences male students from Kharazmi University voluntarily participated in this study. Subjects referred to the laboratory during two days, with 48 hours intervals between each sessions, and lower extremity kinematics data were collected from 30 pedaling cycle on the stationary cycle in 70 RPM in situation of without stretching, after 2, 5, and 10 minutes post stretching by means of motion analysis camera in 50 Hz frequency. Hip, knee and ankle joints angular displacement and velocity were extracted for constructing time series and variability calculation. Results of repeated measure ANOVA did not show any significant differences in angular displacement and velocity variability in hip, knee and ankle joints after 2, 5, and 10 minutes post stretching (P>0.05). Regarding results, probably it can be use static and dynamic stretching in warm up programs before cycling or rehabilitation on stationary cycle.

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.

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.

Functional Movement Screen Test is one of the tests used to identify asymmetries and limitations in basic and fundamental movements. For time management and fast execution of this test, some researchers have suggested reducing the number of tests. The purpose of the present study was to investigate the internal consistency and correlation between components of this test. The present study was a correlational study. In this study, movement screen test was performed on 165 male and female students aged 18 to 25 years of Shahid Beheshti University using a special FMS kit. Results The internal consistency of the test, measured by Cronbach's alpha method, was acceptable (α=0.71). The results of multivariate regression test showed that there was a low to medium correlation between the internal components of the test, but a high correlation was observed between the test components and the final FMS score. The results also showed a high correlation between the "four small movements" (Active leg raising, shoulder mobility, stability push up and rotary stability) and the total FMS score and a low correlation between the "three big movements" and the FMS score. Motor function screen test is a valid tool for evaluating motor performance. The results also show that in large communities such as students, and if there is a time limit, "four small movements" can be used instead of seven.

The kinematic analysis of elite athletes’ performance is an important method to determine effective parameters of sport performances. The purpose of the present study was to compare kinematic characteristics of the upper extremity in adolescence and adult players in three-step shoot in Handball.

Nine elite adult handball players working in the Super League (23.55 ± 2.69 years) and ten teen handball players (16.4 ± 0.69 years) participated in this study. The pictures related to the final stage of the shoot were recorded three dimensionally and analyzed by a graphic interface in MATLAB software. The data related to the angular position, angular velocity and peak angular velocity and position corresponding to the upper limb joints of athletes, including the wrist, elbow and shoulder were obtained. Statistical data were used for analysis through student t-test for two independent groups with significance level p ≥ 0.05 in order to compare two groups.

There were significant differences between two groups in angular position of elbow joint during extension at maximum angular velocity and linear velocity of the ball at the time of the release.

it seems that other factors than cinematic characteristics such as anthropometric characteristics along with muscle strength in adult are important to get the maximum velocity of ball release.

Covid 19 disease is associated with a wide range of clinical symptoms and long-term complications. For most sports medicine professionals, it's a new challenge for people to resume their previous activities after recovering from Covid 19 after receiving the exercise prescription and care. The aim of this study was to review the appropriate physical activity for those recovering from Covid 19 infection based on the type of involvement they developed during the illness. For this study, a review study method was selected. This is done in three steps. In the first stage, physical activity in Quid, in the second stage, organ involvement in Quid, and in the third stage, sports prescriptions in organ involvement by searching for appropriate keywords in reputable scientific databases such as Pubmed, ACSM, SID. ir and Science Direct were searched, content related to the purpose of the articles were extracted and collected and analyzed for content. Examination of organs after recovery from Covid 19 infection is essential to return to physical activity. Physical activity prescriptions in those recovering from Corona varies from disease to patient, and organ to organ. Exercising in Covid conditions requires consideration. The cardiovascular, respiratory, blood, gastrointestinal, and musculoskeletal systems are affected by Covid 19 infection. Exercise, on the other hand, has different effects on the immune system depending on its severity, and the immune system undergoes changes in Covid 19 disease. The type, intensity, and duration of exercise or physical activity vary according to the patient and the symptoms or side effects left by Quid, and the readiness of the various organs for physical activity should be assessed.

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.

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.

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.

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.

Hyper-kyphosis anomalies are common disorders of spine. The aim of this study was to Establishment of dynamic postural assessment indicators in young girls with and without hyper-kyphosis.In the study, 200 girls were selected according to the angle of kyphosis they were divided into two groups comprising of with and without Hyper-kyphosis. Evaluate dynamic posture, the tests back flattening, wall angle position, bilateral forward reach, pelvic tail tuck, head hanging forward, shoulder mobility, shoulder range in internal rotation and external rotation were used. The results showed a significant difference between the partial and general scores of the dynamic body condition assessment test for girls, with and without Hyper-kyphosis. The normal kyphosis group had better dynamic posture than the Hyper-kyphosis group. Dynamic body posture assessment tests can be considered good tool to assess and identify the limitations and movement disorders of people with Hyper-kyphosis.

Considering the prevalence of pain and disability in the knee joint, the present study investigated the effect of core stability training with improving knee joint proprioception on balance, pain and functional disability of women with chronic knee pain. 20 women aged 30 to 50 with chronic knee pain were placed in two experimental and control groups. To measure static and dynamic balance, pain and functional disability, the stork balance tests, Y, VAS and VOMACK questionnaire were used, respectively. Exercises were followed for eight weeks in the experimental group. To evaluate the research hypotheses, the analysis of variance test with repeated measurements was used in spss software version 24. The results showed that before the exercise protocol, there was no significant difference between the control and experimental groups in any of the measured variables. While the eight-week training protocol caused a significant difference in static and dynamic balance, functional disability and pain between the control and experimental groups. Therefore, core stability training with improving knee joint proprioception increase balance in people with chronic knee pain, which can reduce the risk of falling in these people and improve the quality of life by improving pain and functional disability.