جستجوی مقالات مرتبط با کلیدواژه « Isokinetic Strength » در نشریات گروه « تربیت بدنی »

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.

Swimming is one of the most popular disciplines in the Olympics and is popular among athletes. Injury in this sport is often due to repeated repetition of high and repetitive movements. Many researchers Muscle strength is considered one of the most important risk factors. The power of cuff rotators is one of the main risk factors for a shoulder injury.

The statistical samples of this study consisted of 28 swimmers of 12 to 14 years old girls practicing in Alborz Province Swimming League who have been practicing swimming regularly for at least 5 years. In order to perform this study, the maximum isometric and isokinetic contractions (speeds of 60, 90, and 180 degrees per second) in the internal and external rotators of the arm and proprioception of the shoulder joint (45 and 90-degree angles) were measured with the isokinetic device. Then they practiced with TRX for six weeks, after which the measurements were repeated.

The results showed that there was a significant relationship between six weeks of TRX training on isokinetic power at speeds of 60, 90 and 180 per second in eccentric and concentric contractions (P˂0 / 5) as well as isometric strength of internal rotators and External and proprioception of the shoulder joint at 90 and 45-degree angles were significantly different

it can be stated that shoulder injury prevention programs are very important, especially in rotator cuff muscles, for swimming athletes, and strengthening these muscles with TRX is effective because it has positive effects.

Muscle strength is needed for performing many movements and skills in football like speed decreasing, shooting, dribbling, rotating, and jumping. Several studies shown that lower limb muscle strength can increase the quality of exercise skills. But few studies have compared the strength of players at different levels. Therefore, the present study intends to investigate the strength of the isokinetic and isometric knee muscles of the elite, sub-elite and amateur football players of Iran. For this purpose, the isokinetic strength of the knee muscles in 102 soccer players including 29 players of the national under-23 football team of Iran (elite), 29 players of 1st division of under-23 football team of Iran (sub-elite) and 44 players of 2nd division of under-23 football team of Tehran province (amateur) was measured for angular momentum of 60 and 180 degrees per second by the isokinetic Biodex System 4. The isometric strength of flexor and extensor muscles of knee were measured at an angle of 60 degree. The results of the ANOVA test showed that there is a significant difference in strength of flexor and extensor knee muscles in both momentum angles of 60 and 180 degrees per second and flexor/extensor isokinetic strength ratio at 180 degrees per second speed between elite, sub-elite, amateur. However, there was no significant difference in the ratio of flexor /extensor isokinetic strength ratio at 60 degrees per second. Also, there was a significant difference in isometric strength of the extensor and flexor muscles at knee flexion angle of 60 degrees in the three groups. Considering the results of the present study, it can be concluded that exercises and the competition level affect the isokinetic and isometric strength of the knee muscles of young football players of Iran.