[Upper quarter functional stability in female volleyball players with and without anterior shoulder instability, with consideration of arm dominance]

Objective: The aim of this study was the comparison of the functional stability of dominant and non-dominant shoulder in female volleyball players with and without anterior shoulder instability, using YBT-UQ

Materials and Methods: In this descriptive study, 28 female university volleyball players [age=20 to 25 years] were categorized into healthy [n=14] and anterior shoulder instability [n=14] group. Upper quarter y balance test [YBT-UQ] was used for measuring functional stability of both dominant and non-dominant shoulder. After checking the normal distribution of the results with 1-s Kolmogorov-Smirnov, paired sample t-test and independent sample t-test were used for comparing the dominant and non-dominant shoulder's functional stability and for comparing the results between groups, respectively

Results: Higher YBT-UQ composite score was observed in non-dominant shoulder and dominant shoulder of the healthy group and the non-dominant shoulder and dominant [injured] shoulder of shoulder instability group, respectively. No significant difference was observed between functional stability of both shoulders of the healthy group [P=0.144], while the functional stability of the non-dominant shoulders of the instability group was significantly higher than the dominant unstable shoulders [P=0.001]. The results of functional stability of the unstable shoulders of the injured group were significantly lower than the results of the dominant shoulders of the healthy group, while in non-dominant side, all directions but the Superolateral direction showed significant difference

Conclusion: Based on the results of this study, functional stability of the unstable shoulder of female university volleyball players is lower than the functional stability of their non-dominant side or the functional stability of the healthy subjects; Therefore, we suggest that the upper extremity stabilization exercises, specially the closed kinetic chain exercises should be added to the shoulder rehabilitation programs

[The comparison of the amount of EMG activity of the selected involved muscles in hip strategy in female athletes while standing on one leg on shuttle balance and wobble board]

Background and Aim: Use of shuttle balance which has recently been produced in Iran seems to be beneficial in exercise programs for prevention of sports injuries and facilitating recovery. The purpose of this study was to compare the amount of the electromyography activity of the muscles involved in hip strategy while standing on one leg on shuttle balance and wobble board

Material and Methods: In this comparative study we measured the amount of EMG activity of selected muscles [rectus femoris, hamstring, rectus abdominis and erector spine, as the most important involved muscles in hip strategy], in 15 female students of faculty of physical activity and sport sciences of Tehran university by surface electromyography during standing on one leg on shuttle balance and wobble board. The findings were compared using multivariate variance analysis

Results: The results showed a significant difference between shuttle balance and wobble board in regard to the amount of EMG activity of involved muscles in hip strategy[P=0.001]. Also the results showed that the rectus abdominis muscle on wobble board and the rectus femoris and hamstring muscles on shuttle balance had significantly more electromyography activity [P<0.05]. There was no significant difference in erector spine EMG activity between the two devices [P>0.05]

Conclusion: It seems that standing on shuttle balance can lead to higher electromyography activity in the muscles of knee joint [rectus femoris and hamstring]. So we recommend use of shuttle balance in balance training programs

[ relationship between craniovertebral [CV] angle and neck pain among male and female students with an emphasis on different educational levels]

Objective: Neck pain is a common cause for which people refer to physiotherapy centers. Neck pain may be related to prolonged static posture in head, neck, and shoulder during daily activities and studying. The purpose of this study was to investigate the relation between Forward head posture [FHP] and neck pain in female and male students of different educational levels

Materials and Methods: 1017 students [511 girls, 506 boys] from the University of Tehran in undergraduate, graduate and PhD level participated in this correlation study. Selection in departments have been target, however sample, s selection have been random. The mean of age of girls and boys was 23.78 +/- 3.74, the weight was 63.24 +/- 12.1, and height 162.42 +/- 7.14 and boy's age was 23.74 +/- 3.91, weight 57.23 +/- 8.87, and height 168.53 +/- 9.74.FHP was measured in students by questionnaire, visual analog scale [VAS] and by using the Head Posture Spinal Curvature Instrument [HPSCI]. Spearman correlation test was administered to analyze the data using SPSS 18 software [P and le0.05]

Results: Neck pain was significantly and negatively correlated with FHP in female PhD students [P=0.007], while this relationship between undergraduate, graduate students and male PhD students was not significant [P>0.05]

Conclusion: Neck pain is associated with forward head posture in PhD students. Therefore, it is important to address these faulty postures and correct them in treatment sessions. However, due to the progression of student community to higher education level, it is more critical to be aware of the correct of posture position in students

Acute effect of static stretching of quadriceps, hamstrings and gastrocnemius muscles on knee joint position sense in football players

Purpose: Everything that impairs joint proprioception system can harm joints. It has been stated that stretching exercises can change properties of the proprioceptive receptors and as a result changes the sensibility of the joints proprioception. Due to fact that static stretching has greater use between athletes, it is necessary to give useful information about the safety of these stretching exercises and their effect on knee joint position sense. Therefore, the purpose of this study was to determine the effect of static stretching of selected muscles around knee on knee joint position sense in football players

Methods: This study was a quasi-experimental research with pretest and posttest design. In this study, 30 soccer players at the college level, with the mean age of 23.20 +/- 1.45 years were selected through purposeful sampling. Before performing stretching exercises and measuring, subjects had 5 minutes warm up on a fixed bike with the same speed. Then, knee joint position sense were measured by electrogoniometer SG150 model and the achieved figures were recorded as pretest record in the record sheet. Then static stretching exercise protocol was applied on the selected muscle and immediately after that, joint position sense was measured. The obtained data were recorded as posttest record. The paired t test was used to compare the mean of pretest to the posttest mean

Results: The results of the study showed that there is no significant difference between the mean of knee joint position sense before doing static stretching exercises and thereafter [P = 0.13]

Conclusion: According to the results of this study, athletes, trainers and coaches can use the static stretching without fear of negative effects on the proprioception

Investigation of Gluteus Medius and Biceps Femoris activity in three plyometric exercises

Purpose: This study was accomplished to investigate the electromyographic activity of 3 plyometric exercises [tuck jump and single leg hop in sagittal and frontal planes] to find out the appropriate procedures for strengthening biceps femoris and gluteus medius muscles

Methods: The kind of study is applied and data were collected from the supervised exercises of 15 male athletes without injury of lower extremity from Tehran University, which participated voluntarily in this research. It was assumed that subjects expend the extreme potential during their activities. Statistical analysis was made using repeated measures ANOVA to investigate the muscle activity in feedforward and feedback phases of landing with SPSS 20

Results: Significant differences [P

Conclusion: According to the results, single leg hop in sagittal and frontal planes could be the most appropriate exercises for improving strength and neuromuscular system of gluteus medius and biceps femoris. We should take special attention to these 2 plyometric exercises in exercise programs. However, tuck jump in comparison with 2 other exercises show less effectiveness