Publication Date: 2023
Journal of Bodywork and Movement Therapies (13608592)34pp. 6-12
Background: Chronic ankle instability (CAI) is a common injury among athletes. Research has reported reduced dorsiflexion range of motion, impairment of proprioception, and decreased muscle strength of the ankle in people with CAI. The aim of this research was to examine the effects of 8-week core stability training on stable and unstable surfaces on ankle muscular strength, proprioception, and dorsiflexion range of motion (ROM) in athletes with CAI. Methods: Thirty-six athletes with CAI (age 22.42 ± 2.76 years; height 169.11 ± 3.52 cm; weight 68.46 ± 2.75 kg) participated in this study. They were divided into three groups: unstable-surface group (UG) (n = 12), stable-surface group (SG) (n = 12), and control group (CG) (n = 12). The UG and SG performed the core stability exercise protocol for 8 weeks, 3 sessions per week. The CG received their usual care and daily activities. Outcomes were measured pre-sessions and post-sessions. Results: The peak torque showed significant increases in the UG and SG compared with the CG during plantar flexion, dorsiflexion, inversion, and eversion (P < 0.05). There were also significant increases in UG compared with SG (P < 0.05). The proprioception showed significant decreases in UG compared with SG and CG (P < 0.05). The dorsiflexion ROM showed significant increases in UG and SG compared with CG. There were also significant increases in UG compared with SG (P < 0.05). Conclusions: It seems that core stability exercises on trampoline surface helps improve the measured parameters in athletes with ankle instability. Therefore, this type of training is recommended as a therapeutic option for Individuals with CAI. © 2023 Elsevier Ltd
Publication Date: 2022
Journal of Military Medicine (17351537)24(2)pp. 1115-1122
Background and Aim: The aim of the study was to investigate the effect of selected exercises course on the scores of the Functional Movement Screening (FMS) test among the special unit staff of the Isfahan police force. Methods: The present study is quasi-experimental and prospective. The statistical sample of this research included 20 officers of the police special staff (NOPO) who were equally divided into two the experimental group (n = 10) and the control group (n = 10). Demographic characteristics of the special police force staff included mean age: 32.9 ± 2.68 years old, height: 176.80 ± 5.44 cm, and weight: 78.40 ± 8.84 kg. First, the subjects 'functional screening test scores were recorded, then they exercised for 8 weeks (3 sessions per week), and each session was allocated to one hour of selected exercises. Later, the subjects' functional screening test scores were recorded again. Due to the non-normality of the data, a non-parametric Wilcoxon test was used and the data were analyzed by SPSS software. Results: Eight weeks of selected exercises affected the FMS test score on four tests stepping over the obstacle (P = 0.008), launch (P = 0.009), stability push-ups (P = 0.046), and rotational stability (P = 0.015). However, it had no effect on four tests shoulder motion (P = 1.000), deep squat (P = 0.317), and active leg raising (P = 0.83), and the significance level in the present study was 0.05. Conclusion: The findings show that the selected exercises on the special police force staff are weak in the shoulder and squat movement pattern, and active leg raising, but have a positive impact on the pattern of stepping over the obstacle, launch, stability push-up, and rotational stability. Therefore, the functional movement screening test, as a method of injury prevention, are effective for the special police force staff. © 2022 Baqiyatallah University of Medical Sciences. All rights reserved.
Publication Date: 2021
Koomesh (16087046)23(5)pp. 627-635
Introduction: Sexual function and quality of life (QOL) are compromised in female with multiple sclerosis (MS). Recent studies emphasize on functional suspension training using body weight resistance against gravity. Therefore, the purpose of this study was to determine the effect of total body resistance exercise (TRX) on sexual function and QOL in patients with MS. Materials and Methods: Among 93 female patients referred to Isfahan Multiple Sclerosis Society (IMSS) 34 females in the age range of 20 to 50 years with expanded disability status scale of 1-4 were selected as a statistical sample. The participants were intentionally selected into two of control (n=15) and experimental (n=19) groups. The experimental group received the TRX program for 8 weeks and the control group received their usual care. Results: The results showed that there was a significant improvement in physical function (P=0.001), role limitations due to physical problems (P=0.001) and emotional (P=0.015), physical health (P=0.018), sexual function (P=0.018) and sexual satisfaction (P=0.040) of the experimental group compared to the control group. However, no significant differences were found n relation to pain (P=0.485), emotional well-being (P=0.468), energy (P=0.459), health perceptions (P=0.600), social function (P=0.116), cognitive function (P=0.896), concern about their health distress (P=0.118) and mental health (P=0.091), between the two groups. Conclusion: TRX has the necessary components to improve the physical dimensions of quality of life and sexual function of patients with MS. © 2021, Semnan University of Medical Sciences. All rights reserved.
Publication Date: 2021
Journal Of Rehabilitation Sciences And Research (23456159)8(2)pp. 51-56
Background: The purpose of this study was to compare the effect of eight-week shoulder girdle, pelvic girdle and combined corrective exercises on maximal voluntary ventilation in female students with upper crossed syndrome. Methods: In this experimental randomized clinical trial, 45 female college students with upper crossed syndrome voluntarily participated and were randomly divided into three equal subgroups including shoulder girdle group, pelvic girdle group and combined group. The three groups performed corrective exercises of eight weeks and three times per week. The maximal voluntary ventilation was assessed before and after intervention. Results: The results showed that the main effect of group was significant (P=0.029). The Least Significant Difference (LSD) post-hoc test demonstrated significant differences between combined groups with shoulder girdle group (P=0.048) and pelvic girdle group (P=0.011), but no significant differences between shoulder and pelvic groups (P=0.537). The results showed a greater maximal voluntary ventilation in the combined exercise group than in the other groups. The main effect of time was significant for the three groups (P=0.000). There was a significant interaction of groups by time for outcome measurement (P=0.000). Conclusion: The results of this study provided preliminary guidance for the use of the comprehensive corrective exercises for simultaneous correction of anomalies. © 2021 Tamkang University. All rights reserved.
Publication Date: 2020
Journal of Sport Rehabilitation (10566716)29(2)pp. 192-199
Context: Muscle weakness and sensory deficits cause impaired balance and walking abilities that are prerequisites for independent activity of daily living in people with multiple sclerosis (MS). Recent physical exercises tailored to improve the activity of daily living people with MS have focused on the functional training. Objective: To investigate the effect of total body resistance exercise suspension training on mobility, proprioception, and muscle strength of the knee in people with MS. Design: Single-blind pretest and posttest control group design. Setting: Referral Center of Multiple Sclerosis Society. Participants: Thirty-four women with relapsing-remitting MS were participated in this study. The mean (SD) of their age was 36.44 (4.88) years, and the Expanded Disability Status Scale was 2.35 (0.94). The participants were divided into 2 groups: Control group (n = 15) and training group (n = 19). Intervention: The training group performed the total body resistance exercise program for 8 weeks, 3 sessions per week. The control group received their usual care and daily activities. Outcomes were measured presessions and postsessions. Main Outcome Measures: Mobility was assessed with Timed Up and Go test, 10-m walk maximum test, 2 minute walk test, and 5-time sit-to-stand test. Knee proprioception absolute error and isometric strength of knee flexor and extensor muscles were measured by using a biodex isokinetic dynamometer. Results: In the training group, mobility (P = .001), maximal voluntary isometric contraction of knee flexor and extensor muscles in both legs (P > .05), and the knee proprioception absolute error in nondominant leg at 60° knee flexion (P = .02) improved significantly compared with the control group. Conclusion: Total body resistance exercise is a functional and safe intervention that can improve the mobility and muscles strength of the knee in a short period in people with MS. © 2020 Human Kinetics, Inc.
Publication Date: 2020
Journal of Sport Rehabilitation (10566716)29(1)pp. 102-106
Purpose: Firefighters require a high level of functional fitness to operate safely, effectively, and efficiently. The authors studied the distribution of functional movement screen (FMS) scores in firefighters and examined whether an 8-week corrective exercise program based on National Academy of Sport Medicine guidelines could improve them. Methods: All 524 active firefighters of a city completed the baseline FMS testing. Those who obtained a score of 14 or less, a sign of movement dysfunction, and volunteered to continue their participation were randomly assigned to either an experimental (n = 51) or a control (n = 45) group. Both groups participated in an 8-week training program. The control group used their own usual training routine, but the experimental group used the specific protocol designed for the study. Results: The FMS scores of 43% of the population were less than 14. Repeated-measures analysis of variance revealed a significant interaction between FMS scores of the groups (F1,94 = 165, P < .001). The experimental group showed a 69% improvement from pretest (10.6) to posttest (17.8), whereas the control group showed only a 3% improvement from pretest (11.8) to posttest (12.1). Conclusions: Preceding studies have shown that FMS scores less than 14 increase the injury risk. The findings showed that using our proposed training protocol, low FMS scores could be improved to 14 and higher. Considering the high injury rate of firefighters, the authors suggest administering FMS periodically and to use a training protocol such as ours, to increase functional fitness and reduce injury risk. © 2020 Human Kinetics, Inc.
Publication Date: 2019
Physical Therapy in Sport (1466853X)37pp. 113-119
Objectives: Postural disorders disturb muscle activity and lead to joint dysfunction. This study aimed to evaluate the effects of an 8-week selective corrective exercises program on electromyography activity of scapular and neck muscles in persons with upper crossed syndrome (UCS). Design: Randomized controlled trial. Setting: Exercise evaluation was conducted in a laboratory setting. Participant: Study recruited 30 healthy males with UCS from university students, who were then randomly divided into the control group (age = 20.14 ± 1.71 years; height = 176.86 ± 4.7 cm; BMI = 21.20 ± 1.96 kg/m 2 ) and the exercise group (age = 21.44 ± 2.06 years; height = 174.2 ± 4.0 cm; BMI = 20.62 ± 3.9 kg/m 2 ). Main outcome measures: Electromyography activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), serratus anterior (SA), and sternocleidomastoid (SCM) was recorded before and after 8-week exercise program. Results: T-test results revealed that baseline activity of SA (P < 0.05), had increased while UT (P < 0.05) and SCM (P < 0.05) activity as well as UT/SA (P < 0.05) and UT/LT (P < 0.05) ratios had decreased. In connection with these finding the effect sizes were large. Conclusion: Eight week corrective exercises balance muscles activity and can be used to manage developing upper quadrant musculoskeletal disorders in person with UCS. © 2019 Elsevier Ltd
Publication Date: 2019
Baltic Journal of Health and Physical Activity (20809999)11(1)pp. 34-44
Background: Biomechanical factors are the main mechanism of load applied on the anterior cruciate ligament (ACL). The aim of this study was to evaluate the effect of eight weeks of core stability training on the lower extremity joints moment during a single leg drop landing task. Material and methods: Thirty basketball athletes were randomly assigned into training and control groups. The training group performed core stability training for 8 weeks, but the control group did not perform these exercises. Lower extremity kinetics and kinematics variables during a single leg drop landing test were collected by a motion analysis system and a force plate in a pre-and post-test. Data were analyzed using a mixed repeated measure ANOVA test (p ≤ 0.05). Results: The results showed there was a significant reduction in the moment of flexion, adduction and rotation of the hip and the moment of the knee and subtalar joint in the training group (p < 0.05), while there was no significant reduction in the ankle moment (p > 0.05). Conclusions: Core stability training that was used in this study can reduce the forces exerted on the lower extremity joints during single leg drop landing. So, this study provides evidence that core stability training reduces lower extremity joints moment and may reduce the risk of ACL injury in athletes. © 2019, Gdansk University of Physical Education and Sport. All rights reserved.
Publication Date: 2018
Sport Science (18403662)11(1)pp. 104-109
Patellofemoral pain syndrome (PFPS) is a musculoskeletal disorder of the knee joint. The purpose of this study was to investigate the effect of combined exercise (hip abductor and external rotators strengthening + balance) on muscle strength and postural control in patients with PFPS. In this semi-experimental research, 20 men with PFPS who were accessible were selected purposively and were then randomly assigned to two groups, i.e. the experimental (10) and control (10) groups. The experimental group performed a training program for eight weeks. Muscle strength and postural control in the patients were measured through the handheld dynamometer, static balance (stork test) and dynamic balance (Y test), before and after the exercise. Repeated measures ANOVA were used to analyse the data with P≤0.05. The results indicated that the changes and interactions of all the variables were significant in the experimental group (P<0.05). The results also showed that the experimental group, compared with the control group, had a significant improvement in all the variables (P<0.05). With respect to the effectiveness of training on the improvement of muscle strength and postural control, the rehabilitation experts and therapists can use this research training protocol in the physical rehabilitation of PFPS. © 2018, DPTZK (Physical Education Pedagogues Association). All rights reserved.
Publication Date: 2017
Scientific Journal of Kurdistan University of Medical Sciences (1560652X)22(1)pp. 82-92
Background and Aim: Patellofemoral pain syndrome (PFPS) is an orthopedic disorder of the knee joint which results in pain and impairment of performance. The purpose of this study was to investigate the effect of combined exercise (hip abductor and external rotators strengthening + balance) on pain and performance in the patients with PFPS. Materials and Methods: In this semi experimental study, 20 men with PFPS were selected by purposeful sampling and then randomly assigned to two groups, i.e. experimental (n=10) and control (n=10) groups. The experimental group performed a training program which consisted of hip abductor and external rotators strengthening and balance exercises, 3 sessions per week for eighth weeks. Pain and physical performance in the patients were assessed by Visual Analogue Scale (VAS) and WOMAC respectively, before and after exercise. Repeated measures ANOVA was used to analyze the data. P ≤0.05 was considered significant. Results: The results indicated that the changes and interactions of the two variables of pain (F=14/2 and p=0/001) and physical performance (F=60/2 and p=0/001) were significant in the experimental group (P < 0.05) after exercise. The results also showed that the experimental group, had reduced pain and showed a significant improvement in the physical performance (p<0/05), compared to the control group. Conclusion: Considering the effectiveness of training in the improvement of performance and reduction of pain, this training protocol can be useful in the physical rehabilitation of PFPs. © 2017, Kurdistan University of Medical Sciences. All rights reserved.
Publication Date: 2016
Scientific Journal of Kurdistan University of Medical Sciences (1560652X)21(3)pp. 34-44
Background and Aim: Mothers of children with cerebral palsy have a significantly higher prevalence rate of musculoskeletal pain than the mothers of normal children. The purpose of this study was to evaluate the effect of eight weeks of core stability exercises on pain and functional disability in the mothers of children with cerebral palsy. Materials and Methods: In this semi experimental study which was done in Isfahan, 30 mothers of children with cerebral palsy (age of children between 6 and 18 years), who had chronic non-specific low back pain were selected by convenience sampling method. They were randomly divided into experimental and control groups. Each group included 15 subjects. Experimental group performed core stabilization exercises for 8 weeks. The level of pain and functional disability were measured by visual analogue scale (VAS) and Oswestry Disability Index (ODI) questionnaire respectively before and after eight weeks of exercise program. Data were analyzed by repeated measure ANOVA (P = 0. 05). Results: Our findings showed significant effect of core stabilization exercises on the pain (P=0.001) and functional disability (P=0.001). Conclusion: Based on current results, core stabilization exercise program reduces pain and improves functional disability in mothers of children with cerebral palsy. Considering the positive effect of these exercises on pain and functional disability, this program could be recommended for people with similar problems. © 2016, Kurdistan University of Medical Sciences. All rights reserved.
Publication Date: 2015
Journal of Military Medicine (17351537)16(4)pp. 231-236
Aims: According to the role of exercise on the rate of occupational burnout, the purpose of this research was to compare occupational burnout among athletic and non-athletic military personnel in a military training center in order to evaluate the role of exercise on occupational burnout. Methods: In this descriptive - comparative research, 250 staff from an army training center in the Isfahan province, were selected as an available sample. In order to determine the level of occupational burnout and the rate of physical activity, the Jackson Maslach and Beck questionnaires were used. In the end, data were collected, and were analyzed using t-test as well as Pearson correlation and SPSS 17 software. Results: The most important finding in this study was that all the three dimensions of occupational burnout including emotional exhaustion, depersonalization and decreased personal achievements were lower in athletic military staff compared to the non-athletic staff. Conclusion: As a conclusion, findings reveal that sport and physical activities can increase human being capacity to cope with psychological pressures in the workplace. © 2015, Bagiatallah University of Medical Science. All rights reserved.
Publication Date: 2014
Indian Journal Of Medical Research (09715916)139(JUN)pp. 857-863
Background & objectives: Enhanced muscle strength is seen when resistance exercise is combined with the consumption of nutritional supplements. Although there is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans, but its usage as a nutritional supplement for strength is common in athletes. The aim of this study was to determine the effects of gamma oryzanol supplementation during 9-week resistance training on muscular strength and anthropometric measurements of young healthy males. Methods: In this double-blind clinical trial, changes of anthropometric measurements and muscular strength were studied after chronic resistance exercise and gamma oryzanol supplementation in 30 healthy volunteers (16 in supplement and 14 in placebo). Each day, gamma oryzanol supplement (600 mg) and placebo (the same amount of lactose) were consumed after training. The participants exercised with 80 per cent 1-Repetition Maximum (1-RM), for one hour and four days/week. Anthropometric measurements and subjects' 1-RM for muscular strength were determined at the commencement and end of the 9-week study. Results: There was no significant difference between the baseline characteristics and target variables at baseline between the two groups. After gamma oryzanol supplementation, there was no significant difference in the means of anthropometric and skin fold measurements between the supplement and placebo groups. However, there were significant differences between the supplement and placebo groups for 1-RM of bench press and leg curl, which showed that gamma oryzanol improved muscle strength following resistance training. Interpretation & conclusions: Our findings indicated that 600 mg/day gamma oryzanol supplementation during the 9-week resistance training did not change anthropometric and body measurements, but it increased muscular strength in young healthy males. Further, studies need to be done in trained athletes, women, and in patients who suffer from muscular fatigue.
Publication Date: 2013
World Applied Sciences Journal (19916426)28(12)pp. 2188-2192
Objective: The aim of thepresent study is to determine Reliability and Validity of Ultrasonic Wave Arc Detector Device in Measurement of Lumbar Lordosis Angle Compared with the golden standard X-ray method. Methodology: After making the device, Lumbar lordosis angle of31participants were measured by three examiners three times in at least two hours intervals with the device for determining of its reliability and Lumbar lordosis angle of15 participants were measured through radiographic and proposed techniques In order to measure the device validity. The participants were selected from available individuals and volunteers' people of Birjand city. Findings: reliability ofthe first, secondand third examiners are 0.97, 0.98 and 0.98 respectively and reliabilitybetweenexaminersperiods are 0.96, 0.97 and 0.95 respectively, the Correlation betweentheproposed method andthe reference method is (r=0.95) and it was found to be significant (p≤0.05). Discussion and Conclusion: the high Reliability and validityoftheproposed methodcan be due tothe least interference of examinerinmeasurement process and use of high-precisionengineering andcomputationalmethods. So this method can be used for measurement of lumbar lordosis angle Along with other non-invasive methods can be used as astableand reliablemethod. © IDOSI Publications, 2013.
Publication Date: 2019
Iranian Journal Of War And Public Health (20082622)11(4)pp. 183-188
Aim(s) Injury with chemical agents effects on the physical, mental, social and spiritual dimension of quality of life. The aim of the present study was to investigate the effect of eight weeks of modified Pilates training on pulmonary function and quality of life in veterans exposed to chemical warfare agents. Materials and Methods This semi-experimental study with pretest-posttest design and a control group was conducted in Izeh County in 2016. The study was carried out on 28 male veterans who were exposed to chemical warfare agents. The subjects were selected by convenience sampling method and randomly assigned into the control group (n=15) and training group (n=13). The training group performed the modified Pilates training for 8 weeks, 3 sessions-in 60 minutes per week. The control group did not participate in any particular training program during this period. Muscular strength, pulmonary index, and quality of life of the subjects before and after the training period were measured by hand dynamometer, spirometer, and quality of life questionnaire respectively. Data were analyzed through SPSS 22 software using paired sample t-test and univariate analysis of covariance test. Findings The mean scores of forced vital capacity and the quality of life in terms of mental and physical dimensions in the posttest step were significantly higher than the pretest step (p=0.001). By removing the pretest effect, the mean scores of back muscular power (p=0.03), forced vital capacity (p=0.02) and quality of life (p=0.001) in the training group were significantly higher than the control group. Conclusion Eight weeks of modified Pilates training can be effective in the improvement of pulmonary function and quality of life of veterans exposed to chemical warfare agents. Copyright© 2019, ASP Ins. This open-access article is published under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License which permits Share (copy and redistribute the material in any medium or format) and Adapt (remix, transform, and build upon the material) under the Attribution-NonCommercial terms.
Noori, S.,
Ghasemi kahrizsangi, G.,
Khayambashi, K.,
Karimi, A.,
Minasian, V.,
Alizamani, S. Publication Date: 2011
Journal of Isfahan Medical School (10277595)29(151)
Background: The aim of present research is to compare the effects of exercise therapy and physiotherapy that are two common treatments for pain and disability in patients with chronic low back pain. Methods: In this research 30 patients with chronic low back pain (history of low back pain for at least 3 months) were selected. Patients allocated in two treatment groups: exercise therapy (n = 17) and physiotherapy (n = 13). Disability was evaluated using oswestry low back pain disability questionnaire (ODQ) and pain intensity was evaluated with the visual analog scale (VAS).Two groups underwent treatment for 6 weeks. Post-test was performed at the end of treatment period. Following collection of primary information and determination of different variable, covariance test with the variety factor (pre-test) in the level of α < 0.05 was used to analyze the data. Findings: Research findings did not show statistical significant difference in pain (P > 0.05) but the difference in functional disability between two groups was significant (P < 0.03). Conclusion: Our results indicate that exercise therapy is better than physiotherapy for disability improvement in patients with low back pain. Finally, this study recommends that exercise therapy can be an effective modality to management patients with chronic low back pain.
Publication Date: 2024
International Journal Of Technology (20869614)15(4)pp. 1173-1182
Knee and anterior cruciate ligament (ACL) are among the most injured parts of the body during sports activities. Therefore, this study aimed to evaluate knee torque and mechanical stress on ACL under various conditions of stop-jump landing, as well as identify risk factors for injury, and propose improved strategies. The stop-jump landing was modeled using anthropometric and kinematic data. Knee torque was calculated with the inverse dynamic method, and ACL stress was determined using a Finite Element Model (FEM). Different landing strategies were simulated, including variations in knee flexion at initial foot contact, as well as knee and hip angular displacement. The results showed based on mechanical stress analysis, females (6.30 MPa) had a higher probability of ACL injury compared to males (4.51 MPa). Increasing knee flexion at initial contact caused decreased knee torque and approximately a 7% reduction in ACL stress. Furthermore, increasing knee and hip angular displacement led to a decrease in knee torque, with a reduction in ACL stress by 44% and 11% respectively. To reduce the risk of ACL injury, it is recommended to increase knee flexion at initial contact as well as promote knee and hip angular displacement during landing. © (2024), (Faculty of Engineering). All rights reserved.
Publication Date: 2023
Iranian Journal of Ageing (1735806X)18(3)pp. 304-325
Objectives The ability to safely walk up and down the stairs is an essential factor in older adults’ independence and quality of life. This study aims to investigate the effect of combined exercises on stair negotiation performance of older men. Methods & Materials In this randomized controlled clinical trial, 30 older men with at least 60 years of age living in Isfahan, Iran, in 2021 were selected who had functional independence, mental health, the ability to perform daily activities without using an assistive device, and without a history of falling. They assigned randomly to two parallel groups of intervention and control groups. Participants in the intervention group completed 12 weeks of combined exercise. The center of pressure (COP) parameters were measured by a force plate, and the time of stair ascending and descending was recorded by the Qualisys motion analysis system. The stair negotiation performance was evaluated by the timed up and down stairs (TUDS) test and the stair self-efficacy (SSE) scale. Data were analyzed by mixed ANOVA in SPSS software, version 24. The significance level was set at 0.05. Results The combined exercise program was effective in reducing the COP parameters during stairs ascending and descending (P<0.05). Stance time and time of ascending and descending decreased after the exercise (P≤0.034). The results of TUDS test (P≤0.002) and SSE scale (P≤0.048) showed improved performance in the intervention group compared to the control group. Conclusion The combined exercise program, by focusing on the factors such range of motion, strength, power, and balance, is effective in improving the stair negotiation performance of older men. Due to the prevalence of stair use in daily activities and its potential risk for older adults, this combined exercise program is recommended for older men. © (2023), (Negah Institute for Scientific Communication). All Rights Reserved.
Publication Date: 2022
Sport Sciences for Health (18247490)18(1)pp. 219-225
Purpose: Kinematic variables identify movement patterns and are used to compare successful versus unsuccessful performances that cause to better understanding of performance optimization techniques. Therefore, the aim of this study was to compare the angular kinematic variables in successful and unsuccessful performances in gymnastic somersault for identifying the optimization performance of this technique. Materials and methods: Eleven skillful male gymnasts (Avg. age 11.5 ± 3.7 years, height 123 ± 38.9 cm, weight 36.5 ± 16.9 kg and experience 4.64 ± 3.7 years) participated in this study. They were required to perform somersault and their performances were labeled as successful and unsuccessful performances according to referees’ scores. Then, the recorded performances were analyzed and the desired kinematic parameters were calculated. Results: The results showed that the average of ankle angles at two instances of initial contact and toe off were higher in successful performances than unsuccessful ones. Besides, the minimum values of hip and knee angles and also the maximum values of knee angles were significantly higher in successful performances. The shoulder angles at two instances of initial contact and toe off in successful performances were also found to be less than unsuccessful ones, but, the range of shoulder motion in successful performances were greater than unsuccessful performances. Conclusions: According to the results of this study, the maximum and minimum values of the major joints involved in this technique, range of their motions, and angular velocities of them are identified as the effective factors in this technique. © 2021, The Author(s), under exclusive licence to Springer-Verlag Italia S.r.l., part of Springer Nature.
Publication Date: 2021
Smart Structures and Systems (17381584)27(4)pp. 641-650
In the present study, the generation of electrical energy from induced vibrations in a composite beam with piezoelectric layer are studied. Accordingly, using Euler-Bernoulli beam theory and considering two types of air damping (external damping) and structural damping (internal damping), the equations of motion for sandwich beam are obtained and then using the Kantorovich method, the output voltage relations for a composite beam with a piezoelectric layer are extracted. After validating the analytical results with the results in the literature, the effect of various parameters such as external fluid flow rate, fiber angle, and how the piezoelectric layer composite beams are arranged on energy harvesting. Also, the maximum oscillation amplitude are investigated. The results show that by using composite materials and with proper layer design and fiber angle in each layer, a different equivalent modulus of elasticity can be created in the composite beam, which will change the normal frequency of the system and the output voltage range of the circuit. The results show that the angle of the fibers has a significant effect on the damping coefficient of the structure, flexural stiffness, natural frequency and finally energy harvesting. According to the results, it can be seen that the minimum value of voltage per use of fibers with an angle of 50 degrees and the maximum amount of voltage per use of fibers with an angle of zero degrees are occurred. © 2021 Techno Press. All rights reserved.
Publication Date: 2020
Aging Clinical And Experimental Research (17208319)32(9)pp. 1757-1765
Background: Impairment of postural adjustments in elderly is associated with decreased functional mobility, balance confidence and quality of life. Aims: We studied the effects of anticipatory postural adjustments focused training on postural preparation, balance confidence and quality of life of the elderly. Methods: It was a single-blind randomized controlled trial. The sample included 60 males with history of falling (at least once in the past 6 months). They were matched and randomly assigned into three groups: perturbation, balance, and no training. The electrical activity of the muscles was measured by electromyography. The Activities-specific Balance Confidence (ABC) scale and the SF-36 questionnaire were used to assess balance confidence and quality of life, respectively. Repeated-measures ANOVA was used for data analysis (significant level 0.05). Results: The type of training had significant interaction effect on muscle latency (F(2, 46) ≥ 71.06, P ≤ 0.001, η2 ≥ 0.75). Compared to the other two groups, perturbation training group showed significantly more improvement in ABC scale (F(2, 46) = 14.94, P ≤ 0.000, η2 ≥ 0.39). It also significantly showed more improvement than no training group in all areas of SF-36 questionnaire, except for mental health (F(2, 46) ≥ 6.56, P ≤ 0.03, η2 ≥ 0.22). Conclusions: Our findings support the use of perturbation training, as it reduced the probability of falling (by decreasing muscle latency and increasing posture preparation), improved the balance confidence for daily activities, and improved the quality of life. © 2019, Springer Nature Switzerland AG.
Publication Date: 2020
Iranian Journal of Ageing (1735806X)15(2)pp. 236-245
Objectives Improving balance and motor function in the elderly for preventing falling and its irreparable consequences has attracted the attention of many researchers in the field of aging. The purpose of the present is to investigate the effect of an exercise program based on Anticipatory Postural Adjustments (APAs) on postural control and motor function of the elderly. Methods & Materials In this experimental study conducted in 2017, the study population consists of 38 eligible male elderly people with a history of falls at least once in the last six months living in Isfahan, Iran in two groups: 18 in the test group (mean age =70.4±3.2, mean height=65.3±6.2 cm, mean weight= 65.3±4.2 kg) and 15 in the control group (mean age =69.6±3.1 years, mean height =167±5.5 cm, mean weight =67.3±6.8). A foot-scan device was used to measure their postural control, and the Timed Up and Go (TUG) test was taken to measure their motor function. Data were analyzed in SPSS v. 20 software using repeated measures ANOVA at the significance level of P≤0.05. Results The exercise program significantly improved the mean postural control scores in anterior/posterior direction from 28.1±6.2 to 20.5±2.4 (F=8.21, P≤0.05), in medial/lateral direction from 17.1±1.5 to 13.2±2.9 (F=13.4, P≤0.05), and in overall from 312.4±21.2 to 285.8±17.5 (F=10.02, P≤0.05); It also improved the mean TUG test score from 13.3±2.1 to 10.1±1.0 (F=16.02, P≤0.05). The experimental group showed a better performance than the control group after exercise in TUG test and postural control parameters (P≤0.05). Conclusion An 8-week exercise program focused on APAs can be effective in improving postural control and motor function of the elderly. © 2020, Iranian Journal of Ageing. All Rights Reserved
Publication Date: 2010
Procedia Engineering (18777058)2(2)pp. 2563-2567
The barbell trajectory of snatch weightlifting has been investigated by several researchers. They suggested three optimal trajectory patterns (type A, B and C). But, there is no agreement for introducing the best overall trajectory. One probable reason would be this idea that the selected criterion used by the previous researchers might not be appropriate. Therefore we used a mathematical approach to judge between the conflicts. We made a multi-segments biomechanical model to evaluate the snatch motions while considering the selected mechanical cost. This method is an appropriate tool for coaches to examine several trajectories for making a good decision.
Simulating the snatch weightlifting technique by means of dynamic formulation and optimizing this movement using Genetic Algorithm is the main purpose of this study. Snatch weightlifter is modeled by an open kinematic chain. The problem is defined as the optimization of the movement of this model from the first position to the predefined second position while considering the specific optimum criterion like minimizing the muscular effort. The results for two different weight class are represented in the forms of kinematic and kinetic data like trajectory of barbell and actuating joint torques. Because of some similarities between the results and experimental observations by other researches we conclude that our method can be able to model the real situation. This model can be used to optimize the performance of the weightlifters and it could give us some useful advice about the most effective technique. © 2008 IEEE.
Publication Date: 2008
American Journal of Applied Sciences (discontinued) (15469239)5(5)pp. 524-531
Mathematical modeling and optimizing of snatch lift technique based on dynamic synthesis, is the aim of this study. The barbell trajectory is proposed as the performance index, evaluated experimentally by several researchers who have introduced some optimum trajectories according to the percentage of their owners' successes. Since none of the mechanical parameters were considered into the optimum trajectories, we develop a mechanical approach to fulfill this lack. Therefore, we use a biomechanical model comprised of five links to obtain the optimum trajectory of snatch weightlifting by means of minimizing a criterion function. To achieve this goal, we should solve the differential equations representing the model motion simultaneously with equations representing the performance criterion; therefore we use the optimal control approach via Pontryagin Maximum Principle (PMP) formulation. The performance criterion is defined as minimizing the sum of actuating torques of all joints during the whole snatch. The barbell trajectory of our optimized model is approximately similar to one which could be observed in experimental results. By comparing the results of this theoretical model with experimental observations of other researchers, it could be concluded that we have introduced a good predictive model. Using the biomechanical characteristics of any specific weightlifter as the input data to this model and comparing the results with the same weightlifter's experimental data can help the coaches to improve the performance of weightlifters. © 2008 Science Publications.
Mathematical modeling and optimization of snatch technique based on dynamic synthesis is the main purpose of this study. The barbell trajectory is proposed as the main index which was evaluated experimentally by several researchers who introduced optimum trajectory according to percentage of their owners' success. We believe that in optimizing the barbell trajectory we should consider the mechanical principles. Therefore we use a five-link biomechanical model to evaluate its behaviour and to predict the optimum barbell trajectory which minimizes the specific mechanical criterion by using genetic algorithm (GA) which is theoretically and empirically proven to provide a robust search in complex spaces, thereby offering a valid approach to problems requiring efficient and effective searches. Comparing the results of this model and experimental observations of other researchers, we show an improvement to introduce a good predictive model. Using this model can help the coaches to improve the performance of weightlifters.
