نشریه مطالعات طب ورزشی
پیاپی 38 (زمستان 1402)

Muscle injuries are one of the most common reasons for missed playing time in the football, and the hamstring muscle is one of the most common injures. The role of this muscle in supporting ligaments is also important. In spite of different structural and kinematic features of the hamstring in men and women, a few studies have investigated these differences; therefore, The purpose of this study was to determine the effect of six weeks of Nordic hamstring training on the isokinetic strength of the hamstring muscle of elite female and male soccer players.

24 soccer players (12 female and 12 male) from youth first division league in Tehran province participated in this study. The isokinetic strength of the hamstrings and quadriceps muscles at various angular velocities was measured. After the pre-test, the subjects performed six weeks of Nordic exercise as part of their warm-up.

Performing Nordic hamstring exercises caused a significant difference in the isokinetic strength of the hamstring muscle after the test and at angular speeds of 60, 180 and 300 degrees per second, as well as a significant difference in the ratio of the isokinetic strength of the hamstrings to the quadriceps at a speed of 60 degrees per second between of elite female and male soccer players (P=0.001).

It is concluded that Nordic hamstring exercise improve isokinetic strength of the hamstring muscles and reducing the risk of injury in the knee joint.

Gait mechanics alternation remain after anterior cruciate ligament reconstruction (ACLR). Evaluating the center of pressure (COP) trajectory is one of the variables that reflects whole mechanics of walking and running. The aim of this study was to compare the COP trajectory in people with a history of ACLR surgery. 48 male basketball players (24 with history of surgery and 24 healthy) participated in this study. The barefoot walking and running COP of both legs of the subjects was recorded by the footscan device in two medio-lateral and antero-posterior directions and was calculated in 4 subphases of the stance phase. The results showed that COP trajectory in walking and running was more medially directed in the forefoot push-off subphase in the ACLR group. Also, in the ACLR group, COP of the injured leg in the forefoot push-off subphase during walking and running was more medially directed than the healthy leg. Regarding the results of the present study, it can be concluded that the COP trajectory is different from that of healthy subjects after ACLR. This difference in COP trajectory can result in altered knee loading and increase risk of knee osteoarthritis.

The purpose of this study was to investigate the effect of eight weeks theraband Resistance training on motor function, fatigue and quality of life in women with multiple sclerosis (MS). The population included women aged 20-50 years with MS with an expanded disability status scale between 1-2.5 and members of the Isfahan MS Association. Among the volunteer patients, 30 people with MS were selected by available sampling method and were divided into experimental and control groups (n=15). Subjects of both groups completed questionnaires quality of life and fatigue severity scale of MS patients before starting the training program and participated in the tests of timed up and go and 30-Second Chair stand. The experimental group performed theraband resistance training three times a week for 60 minutes for eight weeks, and the control group performed their daily activities during this time. After eight weeks, all of subjects were reevaluated with the previous tests. Data were analyzed by independent t test and analysis of covariance. The results showed that posttests of timed up and go (P = 0.001), 30-Second Chair stand (P = 0.001), fatigue severity (P = 0.001) and quality of life (P = 0.001) were significantly different between the experimental and control groups. the results of the experimental group showed that 30-Second Chair stand was 37.2%, timed up and go was 32.6%, quality of life increased by 22.9% and fatigue decreased by 22.1%. In general, theraband resistance training with special characteristics are recommended for the rehabilitation of MS patients.

Talent identification programs will pave the way for the participation of people with disabilities in sports and are important for achieving success in the Paralympic Games. The purpose of this study was to identify and rank the important attributes for talent identification in Blind Football. The expert panel including blind football coaches and talent scouts, blind football players, and Experts, researchers, and lecturers in the field of sports for visually impaired people, participated in a 3-round e-Delphi study to reach consensus on the important attributes for talent identification in blind football. Then the list of agreed-on attributes was subjected to an analytical hierarchy process. In this stage, the expert panel, consisted of blind football coaches and talent scouts, ranked the agreed-on attributes according to their importance. The Expert Choice 11 software was used for analyzing the data collected in this stage. The final list of 36 attributes, categorized in 6 groups and ranked by importance, was made. Tactical skills (0.254) ranked as the most important factor for talent identification in blind football, followed respectively by technical skills (0.207), physiological/ physical fitness factors (0.189), anthropometrical factors (0.170), psychosocial attributes (0.117), and disability-related factors (0.063. Talent identification in blind football is a multifaceted process and blind football players are required to be good at all of these agreed-on attributes to be successful in this this Paralympic sport.

The aim of the present study was to analyze video injuries of football players in the 2022 World Cup. For this purpose, the video footage of all the World Cup games (62 matches) was examined by the researcher and the rate of injury prevalence, the mechanism of injury occurrence, the type of collision leading to injury, the time of injury occurrence and the injured area were recorded in the injury report form. According to the results, 127 injuries occurred during 62 matches or 55.96 injuries per 1000 hours of matches. The highest rate of injury happened in the last 15 minutes of the second half (75-90)(21.3%) (P<0.05).Collision was the most common mechanism causing injury (23.6 percent) (P<0.05) and the highest amount of damage occurred in the lower limbs of the players (55.1 percent) and the ankle was injured more than other parts of their body (19.7 percent) (P<0.05).Also, most injuries were caused by collisions (38.9 percent)(P<0.05). The rate of injury in these games was higher than the previous World Cup games. This can be caused by the difference in the definition of injury, the different game system, the difference in the duration and type of preparation and bodybuilding exercises, and the different methods of collecting information. Also, knowing the time of injury and the type of collision leading to injury, the main mechanisms causing injury and the most vulnerable organs during a football match is effective in designing injury prevention programs and helps players, coaches and the medical team.

Recently, kinesiotape has received attention for improving joint position sense, balance, and gait, but existing studies have conflicting findings. The purpose of this study was to investigate the effect of kinesiotape on the electromyographic activity of selected lower limb muscles of athletes with and without chronic ankle instability during balance tests. The activity of tibialis anterior, proneous longus, gastrocnemius medialis and lateralis, soleus, vastus medialis and lateralis and biceps femoris muscles in 12 athletes with chronic ankle instability and 12 healthy athletes during leg stance time and star excursion balance tests to check the level of activity and co-contraction recordrd. Analysis of variance tests with repeated measurements was used to investigate within and between group effects. Findings showed the kinesiotape did not have any significant effect on the level of activity and the co-contraction ratio during the leg stance time test, and there wasn’t also any significant difference between the two groups in the level of activity and the co-contraction ratio during leg stance time test (p˃0.05). In contrast, kensiotype had a significant effect on the co-contraction ratio during the star excursion balance test, but the results between the two groups were not significant (F=2.27, P=0.14). Considering the effect of kensiotype on the co-contraction ratio of muscles during the performance of the star excursion balance test, it is suggested to use it to improve dynamic balance.