عاطفه یاراحمدی

Selection of contraction type to achieve muscle strength and fitness is very important, especially when the main goal is improvement of certain parts of quadriceps. Thus, the purpose of the current study was to compare the quadriceps muscles activity among three types of knee extensor contractions with different loads in young females.
A total of 20 healthy females with the mean age of 24.7±4.5 years, heaight 168.3±9.4 cm, and weight 62.6±7.2 kg, volunteered to participate in the study and performed isometric, concentric, and eccentric contractions with loads weighing 30-80% 1RM weight using isokinetic dynamometer. Measurement of vastus medialis, vastus lateralis, and rectus femoris activity was carried out using 8-channels electromyography. Data analysis was performed running repeated measures analysis of variance and bonferroni tests.
There was no difference observed between dominant and non-dominant lower limb in muscle activity (p>0.05). Quadriceps activity in eccentric contraction was less than concentric and isometric contractions (P=0.000), and vastus medialis and vastus lateralis activities were more than that of rectus femoris (P=0.002). In the lighter loads, vastus lateralis was more active than the other two muscles (P The results of the current study suggest that quadriceps group has the most activity during concentric contraction. The more interesting result is that by changing the contraction type from eccentric to concentric, recruitment of vastus medialis increases. These results are very important for chronic pathological conditions of the patellofemoral joint since these disorders are often attributed to the weakness of quadriceps, especially its medial part.

Patellofemoral pain syndrome is one of the most common knee disorders in the athletes and women. Despite use of water-based exercise in the treatment of musculoskeletal disorders and sport injuries, its impact on the pain and knee function in the patients with patellofemoral pain syndrome has not been investigated appreciably. The present study made a comparison between the effects of water-based exercise and conventional land- based exercise in the female athletes with patellofemoral pain syndrome.
Material and 20 collegiate athletes with patellofemoral pain syndrome were included in this study and randomly assigned to two groups: water-based (n = 10) and Land-based (n = 10) groups. Land – based protocol was performed in the gym and water-based training was implemented in the pool. Exercises were designed to strengthen the hip abductors and external rotator muscles. We used NRS to assess pain intensity, and Kujala and LEFS scale for the assessment of the knee function in various activities before and after the exercises protocols. We used repeated measures ANOVA for analysis of the effects of the therapeutic interventions.
According to the results of repeated measure ANOVA we found significant differences in NRS (p=0.040) and LEFS (p=0.024) after intervention between the two groups. Statistical analysis showed no significant difference in kujala scores between the two groups (p=0.927).
The results showed that water-based exercise as a therapeutic modality was more effective in reducing the pain and improvement of the knee function in the patients with patellofemoral pain syndrome, compared to land-based exercise.

Introduction and aim: The aim of present study was to assess the effect of six weeks Badminton training on changes of stress and cortisol levels in non-athletic female students.
In this study estimated stress of 120 non-athlete students by stress questionnaire (HAD scale). Were measured Among subjects who had suffered highest stress, 30 subjects with a mean age of 86/2 ± 22 years, height 56/5 ± 163 cm and weight 95/4 ± 57 kg were selected. Cortisol were measured by the bloodletting. The subjects were divided into two experimental and control groups as homogeneous. But the control group did not perform any activity. After training protocol variables were measured again in the same conditions. To estimate the effect of independent variables on the dependent variable of the t-test and the independent ttest to compare groups with a significance level (p The results of this study showed that doing a six-week badminton practice reduces cortisol levels (p =0.005), and decreasing stress (p =0.03) in the experimental group.
There was significant change in levels of cortisol and stress in experimental group.

Much evidence has shown that exercise can increase Bone Mineral Density (BMD), but there is still uncertainty about type and intensity of exercise that provides maximum anabolic stimulus and effect especially on bone. The purpose of this study was to compare the BMD of Bastani athletes with those of Soccer Players and age - matched Non- athletes.Subjects comprised of 20 male athletes (10 Bastani athletes and10 Soccer players) and 10 non- athletes aged 30-45 years participated in the present study. The athletes selected from Hamadan clubs, previously had at least 20 years regular activity in their fields. The non athletes had no regular physical activity in their life. Bone Mineral Density (BMD) of the lumbar spine and femoral neck was measured by DEXA. Descriptive and inferential statistics (ANOVA) methods were used to analyze the data. Statistical analysis indicated that BMD at lumbar spine and femoral neck were significantly higher in soccer players and bastani athletes compared to those of non-athletes (P≤0/05). Furthermore, Bastani athletes had significantly higher BMD at lumbar spine compared to soccer players (P≤0/05). Moreover, BMD of femoral neck was slightly higher in Bastani athletes compared to soccer players but the difference was not significant (P≥0/05). The results of the present study demonstrated that Bastani exercise’s similar to other sports activities, can have positive effects on BMD of athletes especially in lumbar spine. Therefore, it is concluded that Bastani exercise is an effective exercise on BMD which can prevent the athletes from osteoporosis.