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Purpose: The purpose of this study was to investigate the kinematic and kinetic variables, which predict anterior tibia shear force during single-leg landing in female athletes. 

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Purpose: This study aimed to examine the effect of Body-Weight-Supported Treadmill Training (BWSTT) exercises on functional ambulation profile in patients with paraplegic spinal cord injury. 

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Purpose: Knee osteoarthritis (OA) is believed to be an important risk factor for falling. Total knee replacement (TKR) is a commonly used choice when other methods are not satisfactory. Proprioception impairment, risk of falling and balance disorder are within the main complications of this method. While multiple protocols have been suggested for TKR, efficacy of early
isotonic exercise therapy aimed at improving body balance after TKR has not been thoroughly investigated.
Methods: In this quasi-experimental study, ten female patients with severe OA, sampled by nonrandomized convenient method were randomly assigned into either “routine”or “early isotonic exercise” groups. The subjects were undergone TKR surgery. The rehabilitation process (being the same for both groups until the second week) was initiated the day after surgery and lasted for 6 weeks. From the second week, the experimental group received progressive, isotonic exercises, in addition to the routine rehabilitation protocol. Static balance was assessed prior to surgery and after the rehabilitation process in both groups by Sharpened Romberg tests.
Results: In both groups, static balance was significantly enhanced after surgery and rehabilitation (P<0.000). Prior to surgery the groups were indifferent according to their static balance scores (P=0.423) but, after surgery and rehabilitation, the patients receiving early isotonic exercise in addition to routine physical therapy, were significantly in better balance condition comparing the control group (P=0.000).
Conclusion: Routine physical therapy with and without early isotonic exercise therapy enhances static balance but, the balance improvement was more pronounced with this type of exercise. Early administration of isotonic exercise therapy in addition to the routine physical therapy program may enhance balance and prevent fall in patients with TKR.

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Purpose: Doing plyometric training with and without the vessel occlusion is an effective practice for rapid increase of muscles strength their hypertrophy. We evaluated the effects of plyometric training with and without the vessel occlusion on electromyographic parameters.
Methods: In this quasi-experimental study, 22 females were selected through convenience sampling method. They were randomly categorized into 2 groups of plyometric training enforcing blood current limitation (30% 1RM) and plyometric training without enforcing blood current limitation (80% 1RM). The volunteers undertook 3 days per week training for 8 weeks. Before and after training, electromyographic parameters of the participants were evaluated. Analysis of covariance (ANCOVA) was used to evaluate changes in maximal elbow extension and flexion forces from pre-exercise session to the post-exercise session. The level of significance was set at P≤0.05.
Results: Plyometric training with vessel occlusion increased electromyographic parameters compared to the plyometric training without the vessel occlusion.
Conclusion: Plyometric training with enforcing current limitations by low intensity is similar to plyometric training by high intensity on electromyographic parameters. Therefore, this kind of training may replace classic plyometric training.

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Purpose: Regarding the high prevalence of low back pain in various communities and the need to determine an appropriate treatment plan for these patients, examining their functional limitation and disability level is of utmost importance. In this regard, one of the important indicators is Lumbar range of motion. Measurement of the range of motion is a common and appropriate method for determining the functional limitation of the spine and also to examine the effectiveness of various therapeutic interventions. This study was conducted with the purpose of examining the reliability of measuring lumbar range of motion using bubble inclinometer and tape measure.

Methods: This methodological study was performed on 20 healthy males (29–52 years old) and 13 male patients with chronic non-specific low back pain (30–58 years old) in 2015. The ranges of lumbar forward and backward and side bending were measured with bubble inclinometer and rotation with tape measure for both groups. Two measurements were conducted in one day with an interval of one hour to examine the within day reliability, and a third measurement was conducted one week later to examine the between days reliability. Statistical inference was made through calculation of intraclass correlation coefficients (ICC) and standard error of measurement (SEM). All data analysis was done by SPSS version 18.

Results: The ICC and SEM values related to the within days and between days reliability were acceptable. The within day and between days ICC range were 0.770–0.982 and 0.835– 0.977, respectively. SEM range was 0.38–1.20. However, the results of the reliability values of between days measuring of extension in prone position, by using bubble inclinometer, in patients with slight low back pain were low (ICC=0.177 and SEM=5.35).

Conclusion: Results of the present study showed that measuring the lumbar range of motion with bubble inclinometer and tape measure (except measuring extension in prone position by using bubble inclinometer in patients with low back pain) was highly reliable. Therefore, these 2 non-invasive and reliable tools can be used to measure the lumbar range of motion and also to follow-up the effectiveness of therapeutic interventions.

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Purpose: Given that weight and body mass index (BMI) are considered as modifiable factors in osteoporosis, the present study aimed to examine the relationship of weight and BMI with bone mineral density (BMD) and bone mineral content (BMC) at the femur and lumbar vertebrae in perimenopausal women.

Methods: In this descriptive-correlational study, we measured the bone density of the femur and lumbar vertebrae (L1-L4) of 40 women in perimenopause stage (Mean±SD age: 42.85±1.86 years; Mean±SD weight: 69.55±10.97 kg; Mean±SD height: 159.42±6.01 cm; and Mean±SD BMI: 27.60±4.04 kg/m2) using a bone densitometry system. The study data were analyzed using descriptive statistics, analysis of variance (ANOVA), the Pearson correlation coefficient, and regression analysis, at 0.05 significance level. All analyses were performed using SPSS v. 21.

Results: Women in the normal group were significantly different from women in the obese group with regard to BMD and BMC (P=0.001). Weight and BMI were positively correlated with BMD and BMC. Weight and BMI, together, could explain 42% and 37% of the variance of BMD and BMC at the lumbar vertebrae, respectively; and 70% and 63% of the variance of BMD and BMC at the total hip, respectively.

Conclusion: The results of the present study support the predictive role of weight and BMI in BMD and BMC. Therefore, future studies are suggested to examine other effective factors with larger samples.

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Purpose: This study aimed to investigate the effect of one intensive training session on the changes of beta-endorphin and serum cortisol levels of elite wrestlers.

Methods: In this quasi-experimental research with one group and pretest-posttest design, 16 elite wrestlers within the age range of 18 to 25 years were purposefully and selected and they voluntarily participated in the research. The subjects performed one session of intensive exercise with the intensity of 85% to 90% of maximum heart rate. The blood samples (5 mL) were collected two times. First it was taken 30 minutes before the exercise and second blood sample was taken immediately after exercise by one expert and two physicians. The data were analyzed by paired-samples t-test using SPSS 17 and α value was set at 0.05.

Results: There was a significant difference between beta-endorphin levels of elite wrestlers before and immediately after the exercise session (P=0.024). The serum cortisol level also increased significantly during the test (P=0.048).

Conclusion: According to the findings of the study, beta-endorphin increase can make happy the athletes. Furthermore, the rise of cortisol level can increase the efficiency of immune system, boost the energy, maintain the body balance, and decrease the pain sensation.

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Purpose: This study aimed to examine the differences in the co-activation of the rectus femoris (RF) and biceps femoris (BF) using the co-contraction index (CI) in aquatic and land environments during a drop-landing task in active and non-active females.

Methods: In this casual-comparison study, 10 active and 10 non-active females volunteered to participate. The CI was calculated from recorded surface electromyographic (SEMG) activity of the RF and BF. To calculate CI, the amount of overlap between the linear envelopes of the agonist and antagonist muscles was found and divided by the number of data points. MathLab software (version 10) was used to process row data. Also, 2-way analysis of variance (ANOVA) assessed differences between groups and environments.

Results: Results indicated that the CI was not affected by activity level in pre- and post-contact (P>0.05) while it was significantly higher (P<0.05) in land environment compared to the aquatic environment.

Conclusion: Our findings show the differences in co-contraction of knee muscles between different environments. Our measure of co-contraction was lower in water compared to land, with no difference between the active and non-active groups. This may indicate that regardless of activity level, an aquatic environment may be an appropriate choice as an early phase in rehabilitation process.

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Purpose: Core stability and leg stiffness are two determinant mechanisms in athletic performance and risk injury. This study aimed to investigate the gender differences and relationship of these two factors in athletes.
Methods: In this cross-sectional study, core stability and leg stiffness of 12 male and 12 female Iranian squash players at national level were examined utilizing McGill’s test (including flexor, extensor, left side bridge and right side bridge tests) and hopping test at 2.2 Hz. Total core stability was calculated by integrating its 4 parts and their ratios which were considered as balance criteria of core stability. Leg stiffness was normalized to body mass. Independent t test and Pearson correlation test were performed to investigate the research purposes. All statistical analyses were done using SPSS 16.0.
Results: The core stability in two groups had no significant difference. However, the female group had more unbalanced core stability than male group. Leg stiffness was higher in male group than the female group but this difference disappeared after normalizing body mass. The significant correlation between core stability and leg stiffness was explored (r=0.46, P=0.02).
Conclusion: Although the female participants of the study achieved the same scores as males, their unbalanced core and possible adopted strategy to compensate their less stiff structures, may expose them to greater injury risk. These results are noteworthy for designing training programs and choosing proper movement strategies. The significant, but weak correlation between variables indicates the power transmitting role of core musculature in leg stiffness regulation during hopping that should be considered.

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Purpose: Given that physical activity is the most important environmental moderating factor, it has been known as an effective, available, low-cost and non-pharmacological approach to increase or maintain bone density at different ages. The purpose of this study was to investigate the effect of 12 weeks of training in water, on land and combined environment on bone mineral density in premenopausal women.
Methods: In this quasi-experimental study with a pretest-posttest design and a control group, 40 premenopausal women aged between 40 and 45 years were divided into four groups (with 10 patients each) based on the exercise environment: water, land, combined, and controlled. Each group exercised three days a week for 12 weeks, with each session lasting 70 minutes. The lumbar vertebrae bone mineral density of the participants was measured by DEXA before and after 12 weeks and the data were analyzed using descriptive statistics, ANOVA, Analysis of covariance and LSD, with the significance level of .For statistical calculations, SPSS software version 21 was used.
Results: In the combined environment group, the lumbar vertebrae bone mineral density showed a significant increase (P>0.05), while in the control group first vertebra bone density loss was observed for the second and fourth lumbar vertebrae(P<0.05). In comparison with the control group, there was a significant difference among the first and fourth lumbar vertebrae bone mineral density in the water exercise group;first, third and fourth lumbar vertebrae density in the land exercise group; and all lumbar vertebrae density in the combined environment group.
Conclusion: Given that there was no difference observed between water and land exercise groups,exercise in any environment is recommended for premenopausal women because the least effect that exercise can have is prevention of bone loss in these ages.

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Purpose: Anterior Cruciate Ligament (ACL) tear is a common injury among wrestlers. One of its treatments is reconstructive surgery with Hamstring Tendon (HST) autograft. This research aimed to examine the effect of neoprene knee brace on the knee kinetics variables of elite wrestlers after ligament reconstructive surgery with hamstring autograft.
Methods: The present research method is quasi-experimental with pretest-posttest design and a control group. A total of 10 elite wrestlers with average (SD) age of 26.1(2.37) years, average (SD) weight of 78.25(11.32) kg and average (SD) height of 174(3.6) cm all of whom underwent ACL reconstructive surgery with hamstring autograft 6 to 18 months prior to the present research were selected through convenience sampling method. In this research, the selected kinetic variables (ratio of the knee flexor muscles torque to the knee extensor muscles, the average peak torque, maximum power and total work of knee extensor and flexor muscles) were measured by isokinetic dynamometer Gymnex model ISO-1 at 120 degrees per second in two modes of with and without neoprene knee brace with open patella and two adjustable straps. To examine the research hypotheses, the statistical dependent t test at the significant level of 0.05 was used. All statistical analyses were done by SPSS 16.
Results: The findings of statistical tests demonstrated that using neoprene knee brace results in significant changes in the average peak torque, maximum power and total work of the knee flexor muscles and also the ratio of the knee flexor muscles torque to the extensor muscles (P<0.05). Nevertheless using neoprene knee brace did not create significant changes in the kinetic variables of knee extensor muscles (P≥0.05).
Conclusion: Based on the results, using neoprene knee brace could improve kinetic variables, especially knee flexor muscles in elite wrestlers after ligament reconstructive surgery. Therefore, these wrestlers after ACL reconstructive surgery through HST method and performing rehabilitation program can benefit from neoprene knee brace for improving kinetic variables of knee flexor muscles and reducing the likelihood of ligament re-injury during athletic activities.

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Purpose: Because walking is the main activity of humans for movement, many research studies have been conducted to understand its details. One of the main issues in this regard is gait symmetry and the effect of various factors on it. Accordingly, the present study aimed to review the selected factors affecting gait symmetry.
Methods: A literature review was performed on articles published from 2000 to 2016 using Science Direct, Google scholar, PubMed, Ovid Medline, Scopus and Medline databases. The search keywords were “gait asymmetry”, “bilateral coordination”, “bilateral asymmetry”, “limb dominance”, “laterality”, “limb preference” and “performance asymmetry.”
Results: A total of 60 scientific articles were selected according to the research criteria by searching the relevant articles published from 2000 to 2016 in reliable scientific databases.
Conclusion: A review of the previous studies shows that walking in normal people is asymmetric in terms of the lower limb function. Also, limb disorder due to the illness and or disorder creates gait asymmetry. Therefore, regaining perfect symmetry or decreasing gait asymmetry by exercise and intervention in such individuals is considered a method to examine the success of rehabilitation process. However, as factors like movement speed and age can affect gait asymmetry, they should be controlled during the examination of gait asymmetry. Moreover, this information could be useful for gait assessment, clinical prescriptions for patients with abnormalities, designing orthosis and prosthesis, as well as improving the performance of athletes.

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Purpose: The elderly patients undergoing hemodialysis who developed end-stage renal failure are at higher risk for falling and its critical outcomes compared with their healthy counterparts due to of poor balance, reduced muscle endurance, and sedentary lifestyle. The current study aimed at evaluating the effect of selected core stability exercises on balance and muscle endurance in the elderly patients undergoing hemodialysis.
Methods: In the current quasi-experimental study, a total of 30 patients undergoing hemodialysis with the mean age of 62.24±6.51 years, the mean hemodialysis duration of 29.4±18.44 months, and the history of falling at least once during the last year were selected using the purposive convenience sampling method and then, the subjects were randomly allocated into 2 groups of intervention (n=15) and control (n=15). To assess the static balance, dynamic balance, and muscle endurance in the patients, the stork stand test, the timed Up and Go test (TUG), and the sit-to-stand-to-sit test for 60 seconds (STS-60) were used, respectively. The selected core stability exercises were performed for the intervention group in 6 weeks, three 45-minute sessions per week. To analyze data, the repeated measures analysis of variance (RM ANOVA) with SPSS version 22 was used; P<0.05 was considered the level of significance.
Results: Results of the current study indicated significant differences between the groups in terms of static balance, dynamic balance, and muscle endurance (P<0.001). In other words, the implemented exercises significantly affected the studied variables. 
Conclusion: Based on the obtained results, the therapists can suggest the core stability exercises as a safe and functional strategy to improve balance and muscle endurance in patients undergoing hemodialysis, which may result in increased independence of action and reduced risk of falling due to loss of balance. 

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Purpose: As many older people fall during dual tasks, we aimed to examine the effect of different cognitive loads on learning gait stability in younger and older adults.
Methods: 10 younger (Mean±SD age: 25.91±3.42 years) and 10 older adults (Mean±SD: 66.65±4.28 years) were healthy volunteers without a history of falls. They were asked to do three tasks on a treadmill with cognitive load (none, simple, and complex). The Gait-stability Ratio (GSR) was calculated in each condition. Two-way repeated-measures ANOVA was used to examine the mean differences at a significance level of 0.05.
Results: The findings showed that high cognitive load behavior during preferred speed walking in the younger and older adults decreases walking speed, and subjects learn to achieve greater stability. It was determined that by applying different cognitive loads (none, simple, and complex), the GSR value in older adults was higher than younger adults (P<0.01).
Conclusion: The results showed that the older adults, through different walking strategies, especially the lowering phase, provide double support while walking so that they fall less with increasing steadiness. Also, walking exercises along with complex cognitive load can help older adults to better motor control.

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Purpose: Mathematics is a complex subject that includes language, quantity, and space. Students with dyscalculia have difficulty in learning and memorizing numbers, they cannot remember the basic facts related to numbers, and they are slow and inaccurate in calculating. This research aims to investigate yoga therapy as a supplement in the management of students with dyscalculia in Tabriz city, Iran.
Methods: This study is a randomized clinical trial;. a total of 30 male students were initially allocated to either a yoga group (YG, n=15), who underwent a 8-week yoga exercise program, or to a control group (CG, n=15), who did not receive any intervention. The data collection tools are: Visual perception questionnaire, visual and auditory processing questionnaire, spatial visualization questionnaire) and learning disability questionnaire. We performed ANCOVA for data analysis using in level significance 5% by SPSS software, version 25.
Results: The results of ANCOVA showed between-group differences for visual processing (F(1, 18)=19.01, P=0.01), visual perception, and spatial visualization (F(1, 18)=30.132, P=0.001), and spatial visualization (F(1, 18)=5202.86, P=0.001).
Conclusion: It can be concluded that yoga therapy can reduce the amount of math learning disorder in students with dyscalculia.

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