نشریه مطالعات طب ورزشی
پیاپی 31 (بهار 1401)

This study investigated the effect of CXWORX exercises on dynamic balance and proprioception in deaf adolescent girls. The research method was Pseudo-experimental with a control group. The statistical sample was 30 absolute deaf adolescent girls. The subjects were divided into control and experimental groups (15 subjects in each group). Y test was used to measure dynamic balance and upper limb function and kinovea software was used to measure proprioception. Shapirovilk test was used to evaluate the normality of data distribution and dependent t-test and analysis of covariance were used to analyze the hypotheses. It was done in SPSS software at a significant level of 0.05. The results showed that CXWORX exercises improved dynamic balance, upper limb function and proprioception of absolute deaf adolescent girls in both intra-group and inter-group comparisons.

Training loads are important for improving performance and injury prevention. So the present study aimed to monitor training loads and investigate the prediction of non-contact injuries by parameters related to internal and external loads in a Premier League team during a season. 23 players of the Foulad Mobarakeh Sepahan soccer team participated in the study. The training load was measured using GPS and Borg’s questionnaire. The parameters of acute load, chronic load, internal load, acute to chronic load ratio, monotony, strain, and the number of non-contact injuries were calculated. Spearman and Pearson’s statistical tests were used to examine the relationship between variables. Multiple linear regressions were used to evaluate the predictability of injury through load-related parameters. The results showed that acute load, monotony, and strain were directly and moderately related to non-contact injuries. However, these parameters could not predict non-contact injuries in soccer players. It seems that paying attention to these parameters can help coaches to reduce soccer non-contact injury. However, more data is needed in this regard..

The elastic properties and behavior of human body structure are potentially effective on perturbation control and force transmission and so could theoretically be considered as the determinant factors of musculoskeletal injury prevention. The purpose of this study was to determine the relationship between human body elastic behavior and musculoskeletal risk factors during unilateral landing. 30 young healthy men performed hopping and unilateral landing tests on a force plate and in front of a high-speed camera to quantify the elastic behavior and injury risk factors. Leg stiffness as one of the most important parameters of human body elastic behavior and time to stability, knee flexion and knee valgus as some injury risk factors were calculated and their relationships were determined by Pearson correlation test. There were some positive significant correlation coefficients between leg stiffness and initial and final knee flexion angle but there wasn't any relationship between leg stiffness and knee valgus parameters. Another important finding of this study was the positive significant correlation of leg stiffness and time to stability along with anteroposterior axis. According to the results, it seems although high values of leg stiffness is considered as an important factor to success in some movement performances like sprinting, actually it can disturb to adopt a correct landing technique and it can delay the anterior-posterior stabilization. Specific training method modifying the landing technique, regulating the leg stiffness and optimizing the body elastic behavior, can be effective on the prevention of lower body musculoskeletal injuries like ACL injury.

The  aim of this study was to assess the effect of  resistance eccentric and concentric training on electromyographic (EMG) activity ratio  of the  vastus medilais oblique (VMO) to the vastus lateralis muscle (VL). 26 healthy men participated in this study. Training  protocole contained 36 sessions of resistance eccenentric and concentric training at the level of  80 % of one repetation maximum (1RM) on leg press machine. Maximal voluntary contraction (MVC) and EMG activity of the VMO and VL muscle recorded before and after resistance eccentric and concentric training. Maxmimal voluntary contraction of quadriceps and EMG activitiy of the VMO and VL muscle significantly increased after training (P <0.05) and  depended on the training type (P <0.05). Eccentric training resulted in a greater increase in maximal voluntary contraction and EMG activity of  the VMO muscle as compared to concentric training (P <0.05).  The increased EMG activity of the VMO to VL muscle play an important role in patella stabilization, and has commonly been  used  as an effective way to prevent from  lateral patella tilt. Thus, it  is recommended that eccentric training be included in rehabilation program for lateral patella tilt.

The purpose of this study was to investigate the immediate effect of massage on the plantar pressure distribution during gait in people with chronic ankle instability. Fifteen patients with ankle instability participated in this study. Plantar pressure parameters in ten regions were measured pre- and post-massage during gait. The results showed that the peak pressure in the first metatarsal(p=0.034) and the peak force in the regions of the first metatarsal(p=0.03), the mid foot(p=0.045) and the medial heel(p=0.005) decreased significatly after the massage. The time to peak pressure(p=0.041) and peak force(p=0.017) in the mid foot increased significantly after the massage.There was no significant difference in the loading rates of all foot regions after the massage compare to before the massage.Based on the results,‌ the plantar massage as an intervention is proposed to improve the distribution of pressure and subsequently reduce the incidence of re-injury and reduce the negative effects of this type of injury.

The aim of this study was to investigate the effect of changes in pedal width (Q Factor) on knee frontal plane kinematics in cyclists with different Q angles. Three groups of 8 road cyclists (1- Low Q angle, 2- Normal Q angle and 3- High Q angle) cycled in four different pedal widths of 16, 19, 22 and 25 cm. The variables of maximum abduction, maximum adduction, range of motion and mean abduction/adduction angle of the knee joint during cycling were calculated. The results showed that there was significant difference between group 1 and group 3 in the variables of maximum, minimum and mean abduction angle of the knee joint. Also, the effect of changing in the Q Factor was significant on the variables of maximum, minimum and mean abduction of the knee joint. in all variables, the interaction effect between inter-group and between-group factor was not significant. The results of the present study showed that the difference in the Q angle of individuals and also the increase in pedal width affect the frontal plane knee joint kinematics; Therefore, in choosing the appropriate pedal width for cyclists, the difference in their Q angle should be considered.