دکتر حمیدرضا ناصرپور

Long-standing groin pain (LSGP) is a common injury in ball games. This study aimed to compare the electrical activity of selected lumbopelvic-hip muscles during a single leg jump-cut maneuver in football players with LSGP and healthy players.

In this case-control study, 32 football players were divided into two groups: LSGP (n=16) and healthy (n=16). A force plate was used to determine the heel-contact and heel-off moment. The ground reaction forces and the average of three trials of the electrical activity of selected lumbopelvic-hip muscles during a single leg jump-cut maneuver were recorded bilaterally.

At the heel-contact moment, the rectus abdominis and adductor longus muscles on the dominant side and the multifidus muscle on the opposite side showed significantly higher activity in the LSGP group compared to the healthy group (P<0.05). Similarly, at the peak of the vertical reaction force, the rectus abdominis and adductor longus muscles on the dominant side and the multifidus and gluteus medius muscles on the opposite side were significantly more active in the LSGP group (P<0.05). At the toe-off moment, the internal oblique, adductor longus, and gluteus medius muscles on the dominant side and the internal oblique, multifidus, and gluteus medius muscles on the opposite side were also more active in the LSGP group compared to the control group (P<0.05).

Long-standing groin pain causes changes in the electrical activity of muscle groups during different phases of the single-leg jump-cut maneuver, leading to increased dynamic stability and possibly an increased risk of overuse injuries, chronic injuries, economic consequences, and exclusion from sports activities.

Athletic groin pain (AGP) is one of the most common injuries among athletes. It causes the use of compensatory mechanisms to adjust pain and affects lumbar-pelvic and hip movements, which leads to prolonging the pain healing process. This study aims to compare the timing of electromyographic activity in selected lumbar-pelvic muscles during a cross-cutting maneuver in football players with AGP and healthy peers.

In this quasi-experimental study, 28 football players in the second division league of Iran participated in two groups of control (n=14) and AGP (n=14). The timing of electromyography activity in the gluteus medius, adductor longus, rectus abdominis, multifidus, and transverse abdominis/internal oblique during a cross-cutting maneuver was recorded bilaterally with a one-minute interval since the time of foot-ground contact in two groups.

Results:

 The time for the onset of activity in the gluteus medius muscle in the dominant foot (P=0.033) and in the multifidus muscle in the opposite foot (P= 0.023) for the AGP group was significantly delayed in compared to the control group; however, the rectus abdominis muscle in the dominant foot was activated significantly earlier and before the heel contact with the ground (P=0.001).

 It seems that AGP changes the timing of electromyographic muscle activity in football players. These changes and compensatory mechanisms may put the athletes at the potential risk of lower limb injuries. It is recommended to find solutions to reduce the effects of AGP and the resulting changes.

This study aimed to investigate the comparison of isokinetic parameters of hip and knee joint muscles in professional soccer players with athletic groin pain (AGP) and healthy ones.

32 soccer players (control group (n=16) and AGP group (n=16)) who take part in the first and second division league participated in this study. The isokinetic dynamometer with a speed of 90 degrees per second was used to evaluate the selected isokinetic parameters.

The independent sample T-test showed that the mean power and rate of torque development in concentric contraction except in knee flexors muscles was significantly higher in the control group. The relative peak of torque in the adductor muscles group in concentric contraction and the hip and knee flexor-extensor groups in concentric and eccentric contraction was also significantly higher in the control group than the AGP ones. In the control group, the hip extensor muscle torque in concentric contraction occurred significantly at a higher flexion range of motion. The acceleration time of the knee extensor muscle group in concentric and eccentric contraction and the adductor group in concentric contraction was significantly shorter than the APG group.

The present study's findings showed that athletic groin pain could affect the isokinetic profile of the hip and knee joint muscles, which were more pronounced in concentric contraction. It is suggested that coaches pay special attention to concentric contractions in the final stages of an athlete's back to the sport.

 The purpose of the present study was to compare the effects of functional and non-functional fatigue protocols on the dynamic balance of amateur basketball players.

 Ten amateur basketball players (mean age= 21.4±1.5 years, mean height= 177.5±7.1 cm, and mean weight= 67.4±8.5 kg) volunteered to participate in this study. Stair climbing and specific basketball movement circuit training were used to induce the non-functional and functional fatigues, respectively. Dynamic balance was measured by the postural stability test (level 2) using the Biodex balance system. Paired T-test and independent T-test were used for data analysis at a significance level of P<0.05.

 Dynamic balance of subjects was decreased after inducing both fatigue protocols, where the non-functional fatigue protocol reduced the overall balance by 21.39%, and the functional protocol reduced it by 10.49%. There was a significant difference between the pre-test and post-test scores of overall balance and the balance in the anterior-posterior direction following the non-functional fatigue protocol (P=0.03).

 Non-functional fatigue protocol affects the dynamic balance of basketball players more than the functional protocol. Therefore, using different types of specialized exercises to experience the period of fatigue may be effective in improving the balance of basketball players.

Cryotherapy is commonly used in the treatment of acute and chronic athletic injuries. The present study aimed to investigate the immediate effect of cryotherapy on the kinetic factors associated with injury during the side-cutting maneuver in healthy male athletes.

A total of 14 professional athletes (age: 24.3±3.5 years and weight: 74.1±19.2 kg) took part in the study. The kinetic factors, including ground reaction force, and their rate of loading, the center of mass to center of pressure changes, and free momentum, were assessed by force plate during the side-cutting maneuver. Simultaneously, using spray cooling, cold was applied to participants' inside and outside parts of the ankle with a distance of 30 cm from lateral and medial malleolus for 5 seconds; the test was repeated three times. Paired t-tests were used for statistical analysis, with a significance level of P≤0.05.

The results of the Paired t-test showed that both peak ground reaction force (P = 0.042) and the rate of loading in the Medio-lateral direction significantly increased (P = 0.046) after applying the cold protocol compared to the pre-test (before intervention). The center of mass to center of pressure displacement in both Medio-Lateral and Anterior-Posterior directions also showed a significant increase (P = 0.01 and P = 0.004), respectively.

According to the results of the current study, it seems that cold enhances the risk of injuries due to increased force and its rate of loading and reduces the dynamic stability of athletes during the side-cutting maneuver and can put the athletes at risk of potential injuries. It is recommended that further studies be conducted using larger sample size to investigate the use of cooling sprays during the treatment of ankle injuries in shear activities.

This study proposed to compare the isokinetic performance profile of knee and ankle joint muscles in professional and amateur speed skaters. Sixteen speed skaters divided into two groups of amateurs and professionals were included in this survey. Isokinetic parameters of ankle and knee joints evaluated by using the Biodex isokinetic-dynamometer. Shapiro-Wilk and independent t-test were applied for statistical analysis at the significant level of ≤0.05. Independent sample t-test results showed a significant difference in isokinetic parameters such as the power of knee extensor muscle, power and deceleration time in inversion and eversion between amateur and professionals. It seems that the significant difference between professional and amateur speed skaters in isokinetic parameters is related to neuromuscular ability (power and deceleration time of invertor and evertor muscles groups). It is suggested that these parameters be considered in the training of this group of athletes.

The purpose of this study was to investigate the effect of an 8 week highintensity exercise on selected physiological variables of elite wrestlers. 16 young wrestlers (age 19.1±1 year and weight 74.9±17.3 kg) attending the national Greco-Roman camps participated in this study. Physiological variables included in this study were weight, body fat percentage, maximal oxygen consumption, upper and lower extremities anaerobic power, muscular endurance, agility, and handgrip strength. These variables were measured before and after 8 weeks (24 sessions reviewing and practicing techniques,16 sessions of combat (live) wrestling,8 sessions strength training, 8 sessions interval running, 4 sessions of circuit training, 4 sessions of elastic band training and 4 sessions of plyometric training) specific exercise training. The normality of data was checked by Kolmogorov - Smirnov normality measure samples, and data were analyzed with pair sample t-test to compare variables before and after the training program. Results showed that there were significant differences between weight, body fat percentage, maximal oxygen consumption, the Maximum anaerobic power of upper and lower extremities, upper extremities muscular endurance, and handgrip strength of pre and posttest. According to the results of this study, it seems that the applied training program had the main effect on physiological variables such as weight, body fat percentage, maximal oxygen consumption, anaerobic power, muscular endurance, and muscular strength of elite wrestlers that will increase the qualitative athletic performance.

The aim of the current study was to investigate the ankle injury mechanism and its prevalence among the Iranian Iranian Professional Karateka.

390 Kumite karateka (age 24/5±2/8 years and weight 63/5±11/8 kg) attendant in the national team qualifiers participated in this study. The information of ankle injuries such as history, injury mechanism, and effects of ankle symptoms on ability to perform daily and sports activities was obtained through FAAM (Foot and Ankle Ability Measure) questionnaire. Descriptive statistics (mean and standard deviation) were used to describe the data, and Pearson's correlation test was used to determine the relationship between daily and sport FAAM subscales and self-reported scores with a significance level of (P≤0/05).

86 percent of the karateka’s in the present study had ankle sprains and injuries, and the most injuries occurred during the competition. The most important mechanism of ankle injuries was abrupt rotation of the foot and kicking the opponent, and in most cases subjects did self-treatment and did not see a physician. Correlation coefficients of the scale of daily and sports activities with athletes' self-reported scores were (r=0/588, P=0/000*) and (r= 0/742, P=0/000*), respectively.

Regarding the prevalence of ankle injuries among athletes, it recommended that special proprioception sense and strengthen protocol in other to reduce the injury’s risk factor. According to the lack of follow-up of athletes in most cases in the treatment and rehabilitation of ankle injuries, it is highly recommended that the post-injury recovery process be monitored by a physician and back to sport with this regard.