علوم حرکتی و ورزش

The aim of present study was to investigate the physiological effects of two regimes of vitamin C on the delayed onset muscle soreness (DOMS). Thirty seven non-athletic female volunteers (age، 22.02 ± 1.54 yrs) were randomly allocated into 4 groups; Group 1: consumed 100 mg vitamin C (n=9); Group 2: consumed 200 mg vitamin C (n=10); Group 3: consumed placebo (n=9); Group4: control (n=9). The treatment groups received vitamin C 1 hr before eccentric actions up to 47 hr after actions. The placebo group consumed identical capsules that contained 100 mg lactose. Muscle soreness was induced by performing 70 eccentric contractions of the triceps muscle of the non-dominant side on a modified arm curl machine. The time interval every action was 3 s with a 10 s rest between them and there was 1 min rest between every 10 actions. Perceived muscle soreness (PMS)، maximal eccentric contraction (MEC)، creatine kinase (CK) enzyme values and elbow range of motion (EROM) were assessed، 1 hr before، and 1 hr، 24 hr، and 48 hr after the eccentric actions. Data were analyzed by two-way analysis of variance (ANOVA) with repeated measures for the time component of the experiment and the following results were concluded: Peak muscle soreness in all groups in the study occurred 48 hr after the contraction except in the group 1 and there was not a significant difference between the 4 groups in muscle soreness. CK activity increased in all groups after eccentric contraction and there was not a significant difference in CK levels between the 4 studied groups. A non-significant reduction of elbow joint ROM was also indicated in all groups of study. There was not significant reduction in MEC in any groups. Therefore consumption 100 or 200 mg vitamin C dose not affect on (DOMS).

The purpose of this study was to compare the EMG activity of Vastus Medialis Oblique (VMO) and Vastus Lateralis (VL) muscles in the single- joint knee extension (KE) and the multi- joint leg press (LP). Subjects performed two maximal voluntary isometric contractions (MVC) and LP and KE actions subsequently performed at individual load، equal 80% of MVC in each exercise modality. 15 healthy men، (mean age 31.93 ± 7.08 yrs، mean height 176.6 ± 5.93 cm، mean weight 72± 12.62 kg) with no previous of knee pain، trauma، surgery، or other joint disease participated in the study.The EMG signal of VMO and VL muscles was recorded bilaterally during both exercises. Results showed no significant difference between LP and KE. However when EMG activity of VMO and VL muscles were compared whit each other، a significant difference was found (p ≤ 0.05)، and in both action the activity of VMO was more than VL. Regardless of the exercise model this suggests the increased demand of involvement may not be equally shared among muscles possessing different anatomical origin and insertion. Motor control plays an important role in rehabilitation in general and patellofemoral joint problems in particular

Muscular strength is generally measured using either of the following methods، one repetition maximum (1- RM) of a weight-lifting exercise، a resisted maximal effort and portable or laboratory-based dynamometry. The 1- RM method refers to measurements of maximum strength using a strength training device such as a barbell or stationary weight-lifting machine. Dynamometry can be divided into two separate methods according to the muscle action involved. Isometric dynamometers assess the force exerted during static muscular actions typically associated with the back، legs and upper limb، e.g. hand (grip). The classical method of recording isometric muscle strength was cable tensiometry، later replaced by use of load cells and force transducers. In experimental studies، maximal voluntary contraction (MVC) is employed as the criterion for muscle strength، typically registered using strain-gauge assemblies. Such devices are relatively inexpensive and convenient to use in and out of the laboratory. Hand grip dynamometers are possibly the most widespread devices for measuring strength however there is concern regarding the strength in the muscle involved in isometric gripping and the generalisation to large muscle group or whole-body strength.The main limitation of such dynamometers is that they do not replicate sport specific activity. Dynamic strength assessment is the preferred method when assessing athletic performances opposed to isometric testing because of the large neural and mechanical differences between isometric and dynamic muscular action. This recommendation is supported by a number of studies that have found a poor association between isometric strength and dynamic performance in strength-based activities.Isokinetic dynamometry is used to assess dynamic muscle action whereby the velocity of limb movement is held constant throughout the range of movement and the resistance applied is equal to the muscular torque during the movement. Such a device allows accurate measurement of torque throughout many limb movements under concentric and eccentric muscle actions. With the subject maintaining a static position، the dynamometer also allows measurement during isometric muscle action. In order to measure absolute strength it is advised that a relatively low velocity is used to allow for production of maximal torque throughout the movement. The protocol used to establish maximum torque can vary، but this function is most often evaluated following several submaximal repetitions and from the first two or six maximal repetitions. Although such dynamometers allow for isolation of specific muscle groups through a single joint motion، they are limited in their representation of typical sports activities. In this paper some important isokinetic parameters relevant to soccer will be discussed.

Using two consecutive gait cycles، simultaneous and bilateral kinetic gait data، the main objectives of this study were a) to identify the main functional roles of ankle، knee and hip extensors/flexors، and b) to determine whether the action taken by these muscle groups appears to be symmetric or not. Gait of our able-bodied subjects appears to be asymmetric with significant differences noted between each two corresponding peak muscle moment values. Using Principal Component Analysis (PCA) as a curve structure detection method، task discrepancies were recognized when comparisons were made between each two corresponding representative moment curves at each joint (local asymmetry). Muscle moment behaved symmetrically when the right limb representative curve was compared to its corresponding principal component (PC) at the contralateral limb. Gait of able-bodied subjects appears to be symmetric، while control and propulsion were recognized as two major roles of the extensors and flexors (global gait asymmetry). Symmetrical behavior of the lower limbs should be considered a consequence of local asymmetry which indicates different levels of within and between muscle activities developed at each joint during gait cycles

The purpose of this study was investigation the effects of classroom furniture on back، neck، lumbar and leg fatigue in students when used them، a total of 203 male students with the mean age (13.6±1.9)، mean weight (48.87±14.40)، and mean height (155±9.87)، respectively from among 32 classes of 8 different schools of the urban community were selected randomly in this study. The results of questionnaire show a signification relationship between the tired feelings of the subjects with every dispositional condition of the classroom furniture. It was noted as well that the height of the blackboard exceeds the normal height of (178.15cm) and lies out of the comfortable sight of the users which has to be (139.5cm)، (p≤0.05). Results showed that tired feeling and pain of the students were mainly due to the application of non-standard furniture. The comfortable or uncomfortable feeling of the users indicating pain and local tiredness were also collected by the distributed questionnaires. The information provided in the questionnaire forms also show that 49/3% of the users were dissatisfied and felt some sorts of tiredness. The tiring condition they complained from with regard to ergonomic disposition of the furniture which were considered included 41/9% in the knee، 24.1% in the leg 51.2% in the back، 47.8% in the neck، and 24.6% from the high blackboard. The current results in addition to the incompatibility of the furniture used by the students with the anthropometrical specifications and ergonomic standards clearly showed that tired feeling and pain of the students were mainly due to the application of non-standard furniture and underlined the observance of necessary standards during the manufacture and equipment of schools.

Physical education (PE) plays a critical role in educating the whole student. Research supports the importance of movement in educating both mind and body. PE contributes directly to development of physical competence and fitness. The benefits of PE can affect both academic learning and physical activity patterns of students. Therefore، the purpose of this study was to describe the status of teaching and conduct of PE course in the first three grades of elementary schools of Iran. The samples of this research included 796 men، 325 women PE teachers’، plus 691 men، and 500 women principals (Superintendent). They were randomly selected from the schools of fifteen different provinces within the five various regions according to their geographical locations. All participants completed researcher designed questionnaires containing questions rating a wide range of contexts for the purpose of evaluating physical education course in elementary schools including the curriculum، the academic degree of teachers، sport equipment and places، finance، community، and school policies and ethos. The result showed that the majority of teachers and principals had diploma or two years college degree; about 70% of teachers were not specialist in physical education. The majority of teachers (25% men and 20% women) had teaching-experience between 1 to 3 years whereas the principals had between 5 to 10 years of experience، respectively. The majority of teacher <50%) were familiar with the behavioral objectives and used them in their lesson plans. Approximately، 40% of the teachers emphasized on fundamental movements and play in their classes. About 58% of them used lesson plan for their teaching. Overall، fewer than 50 of the teacher assigned grade based on fulfillment of behavioral objectives. About 78% of teachers used schoolyards for teaching physical education course. About 27% of the teachers assigned 60% to % 80 of grade for improvement of physical fitness. About 37% of the teachers agreed upon using integrated physical education method for their teaching. According to the findings of the study، it was concluded that the quantitative and qualitative conditions for PE working at the elementary schools are not in a desirable condition، so this convey a warning signal for those in charge of education and training system of the country as well as the students'' parents

Physical education course is compulsory in higher education system of Iran. The curriculum focuses on physical fitness tests and student marks are apparently based on them. Students are dissatisfied with marking system and think it is unfair and biased. This destroys incentive and reduces the probability of a student''s engaging in physical activity. This study aimed to modify the evaluation system of the course. During three subsequent semesters all participants were tested and marked by a new psychomotor test battery accompanied by new standards. The study included the whole population of 2651 female and 992 male subjects (age 18-24 years). Tests were administered by the same standards، but different administrators in every semester. Test Battery included Stork stand test، Sit-ups، 30 meter sprint، Sargent vertical jump، Sit and reach، Pull-ups، T-test، Trunk lift، Phantom chair، and PACER. Demographic data included age، weight، stature، and BMI. A new set of norms and standards were set for evaluation of the course. Distribution line-charts of new marks were compared to older ones. For females، distribution of marks became closer to ideals، whilst for boys it did not take place. Standardization of fitness testing and scoring neither resolved abnormal distribution of final marks nor eradicated dissatisfaction of students with their marks. It is likely that instructors had alternated final marks based on their subjective understanding of achievements of students in affective and cognitive domains. It seems likely if standardization of scores for affective and cognitive achievements is added to standardization of fitness scores، the marking system might improve.

From the beginning of the human civilization many forms and methods of physical training، with consideration to some spiritual or religious believes، social values and/or political exigencies have emerged and some of them for somehow the same reasons have vanished in the course of time. Zoorkhaneh (home of physical strength) and Varzesh-e-Bastani (special kind of physical training) are some of these historically precious legacies of the Mithraic era that are still، more or less، surviving in some parts of I.R. of Iran. This ancient school of thought in human physical education، skill، prowess، and vigor، all in deep concentration and meditation، is still alive and as a legacy of the past deserves much attention to live longer. The purpose of the study was fourfold: 1-Introduce Zoorkhaneh and Varzesh-e-Bastani to specialists in the areas of physical education and sports in a larger scale، 2-provide the grounds for the sport historiographers for more studies in the related areas، 3-provide the basic knowledge about this rich method of physical education for the people who are seeking different ways of physical exercise، 4-contribute to the preservation of an ancient method of physical training that was once one of the bests in the world. The materials presented in this article are based on the experience of the authors، as well as، the extant research documents and books. The article includes information about: definition of a selected number of technical terms and jargons; historical، philosophical and religious background; past and present physical structure; instruments and equipments; session program; and lastly، contemporary aspects and trends of the Zoorkhaneh and Varzesh-e-Bastani.

As life grows more mechanized around the world، most individuals tend to lose interest and even the opportunity for an active life style. Subsequently، this leads to many psychological and physical ailments such as: overweight، muscular and joint pains، mental stresses and depression. To surmount the problem، governments and sport administrators in many countries، including Iran، have devised special procedures and methods in order to encourage participation in physical activities. This article aims to introduce and analyze the following items: A throughout survey of the formation of organized sport for all in Iran، especially after the Islamic Revolution. Definition of the organizations and departments concerned with promoting and developing sport for all among all the layers of society، a survey of objectives and performance of sport for all federation for men and the sport for all Association for women in Iran، Investigation of the performance of the concerned departments in promoting and developing sport for all in Iran، an analysis of current condition of sport for all in Iran. This article intends to present suggestions for the promotion and the improvement of sport for all in Iran، based on the identification of strong and weak points in its performance

The aim of this study was determine the effects of internal versus external attentional focus strategies on the performance and learning in novice children and adolescences. At the practice phase، participants (76 men; 8-9; 10-11; 13-14 years، & right-foot dominant) without prior experience were required to dribble a colorful soccer ball quickly and accurately through a slalom course on the grass field. Participants were randomly assigned to two groups. They asked to recall which part of the foot (internal) was touching the ball or which color of the ball (external) is facing up at 3 random points during the trial. Retention and transfer (external evaluation) performed without instructions or reminder on day 2. Movement time (MT) and errors data were analyzed in analysis of variance with repeated measures on the trials. The internal focus condition had lower errors during practice، but the external focus showed faster MT during transfer.