Dr Shirin Yazdani, Prof Nader Farahpour,
Volume 19, Issue 21 (9-2021)
Abstract
Background and Objective: although it is documented that the spine and hip alignments alter in scoliosis subjects, but the effect of these changes on the lower extremities’ biomechanics have not been well understood yet. So, the aim of this study was to compare hip, knee and ankle joint’s power generation and absorption during gait in patients with adolescent idiopathic scoliosis (AIS) and healthy controls. Methods: Using motion analysis system with 4 Vicon-460 cameras and two Kistler force plates, the kinematics and kinetics of gait was assessed in twenty girls with AIS and 20 matched healthy controls, then the power of the right and left hip, knee and ankle joints in sagittal plane was calculated. Data was analyzed using ANOVA statistical method with significance level of α<0.05. Results: Results showed that in scoliosis group, the peak power absorption of the right knee was significantly 12.5% smaller than that in control group (p=0.01). But, peak power generation and absorption of the hip and ankle joints in both right and left limbs were not statistically differed between the two groups (p>0.05). Conclusion: scoliosis is associated with the smaller power absorption of the knee joint at convex side. This might be linked with unilateral alterations of the joints' moment, joint forces, and the related muscle activity which might impose asymmetrical force to the hip and cause curve progression.
Golnaz Mousavi, Mehdi Varsei , Abosaeed Rashidi, Reza Ghazisaeidi,
Volume 19, Issue 21 (9-2021)
Abstract
The purpose of this article is to biomechanically simulate athlete's leg and compression garment to measure the pressure on a young athlete's leg in order to apply more optimal and uniform pressure distribution while providing a greater sense of comfort when wearing.
The body condition and body shape of the athlete are measured by anthropometric method. Although Using a CT scan of the athlete's body (athlete's limb) and the mechanical properties of the pressure garment (leggings) that made of elastane spacer fabric was simulated by finite element technique. The results of measuring the real pressure on the young athlete's foot were measured and compared by a kikuhime device. The values of pressure applied by the leg in the real state and simulation indicate a maximum error of 14/44 percent (Cross section below the knee and the point behind the leg), a minimum error of 8 percent (Cross section of the ankle and the front point of the leg). Despite the assumptions and sources of error in this simulation, the results show that measured pressure values in the simulation mode with the real mode with incredible accuracy
Leila Nazari, Saba Rahmati,
Volume 19, Issue 22 (12-2021)
Abstract
One of the most important issues in community is health and progress people. Because of durability of a community depends on health each person. In this regard, the present study aims to compare anthropometric, biomechanical and psychological factors between university student and student girls done. Subjects of the study were 86 girls 15-17 years old and 113 university student 18-24 years old, took part randomly in this study. Measure anthropometric, biomechanical characteristic also psychological characteristics including general health (GHQ-28) and personality (NEO-FFI) were measured. The result of independent t-test showed that between percent fat and lean body mass, static balance and muscular endurance and all of the general health factors, there are significant differences between the two groups. In generally the subjects are in the border abdominal obesity and high risks associated health them. Doing prevention programs are essential. One of the most important proceedings for this group doing of physical activity and fitness and have a regular exercise program.
Dr Heydar Sadeghi, Mohsen Ali Darchini, Hossein Nabavi Nik,
Volume 19, Issue 22 (12-2021)
Abstract
Core stability (CS) is a popular term that has evolved into a fundamental concept the much rehabilitation, performance training and preventative programs. The purpose of this study is considering the relationship between CS power and endurance with performance of adolescence athletes. 12 male swimmers participated in the study. McGill Protocol, the core stability power, MBESTT and 30/60 sit-up test were used to measure the CS endurance and power, respectively. Participants' performance was measured as the specific (stroke-index, 100m crawl stroke) and general performance (standing-broad-jump (SBJ), vertical Jump, 9.1 m sprint, shuttle-run, flexibility and seated medicine-ball toss tests). The Pearson correlation coefficient was used to determine the relationship between the CS power and endurance with general and specific athletes' performance. The results showed only significance relationship between trunk flexion with SBJ and seated medicine-ball toss, and flexibility and total CS power score with flexibility. Also, negative significance relationship found between left lateral flexion with shuttle-run test and trunk flexion with stroke-index. The findings of this study showed a weak correlation between CS with specific and general athletes' performance. Based on our findings, there is no necessity for focusing on swimming training programs.
Ms Sepideh Samavati Sharif, Phd Abbas Ferjad Pezeshk, Phd Mohammad Yousefi,
Volume 19, Issue 22 (12-2021)
Abstract
This study aimed to determine the role of strength, expulsive power and range of motion of lower limb muscle on the fencing performance of elite florists. In this study, eight elite fencers’ participated. Kinetic variables measured using force plate and kinematic variable measured using motion analysis system. The squat jump test used to measure the compulsive power of the lower extremity muscles of the fencers. The Drop-jump test used to measure the lower strength of the muscles of the lower extremity muscles. Descriptive statistics (mean and standard deviation) used to describe the data and Pearson correlation coefficient used for determine the relationship between data (P≤0.05). The results of this study showed there is a significant relationship between squat jump power and mechanical energy and drop jump height with lunge speed and also between ankle range of motion with peak force and impulse in the anterior direction (P<0.05). Given the results of this study, coaches should have a special attention on the strength and explosive power of plantar flexor muscles.
Dr Amir Ghiamirad, Mr Farhad Esmkhani, Mr Salar Hariri,
Volume 19, Issue 22 (12-2021)
Abstract
The aim of this study was to investigate the kinematic characteristics of the two skills of Judan and Chudan Giakozuki Karate, professional and semi-professional male men. Methods: 10 Professional and 10 semi¬-professional amateur male Karate athlethes participated in this study and performed the techniques. The ground reaction force during the impact, which was an indirect parameter to calculate the impact power, was measured using a force plate with a frequency of 250 Hz. The ADXL320 accelerometer was also used to calculate the hand transfer acceleration. The motion data were recorded using Phase Space real time optical tracking system with 8 high speed cameras at 480 fps. Then the kinematic parameters associated with each fist were modeled and quantified by a three-dimensional imaging system.Paired t-test and independent t-test were used to analyze the research data.The test results in the parameters of wrist, elbow, shoulder movement in Judan and Chuadan Gyakozuki skills, ground reaction force, peak speed of elbow and shoulder in Chuan Gyakozuki skill, peak wrist velocity in Judan Gyakozuki skill in semi-professional karate and professional showed a significant difference. Fainaly, the results showed that the type of impact and the level of experience of karatekas were the main factors in determining the size of the displacement parameters and peak velocity, which are considered an important factor in success in competitions and lead to better scores in competitions.
Vahideh Ranjbari, Mehdi Rafei Borujeni, Shahram Lenjannejadian,
Volume 20, Issue 23 (9-2022)
Abstract
Introduction and aim: The kinematic analysis of elite athletes’ performance is an important method to determine effective parameters of sport performances. The purpose of the present study was to compare kinematic characteristics of the upper extremity in adolescence and adult players in three-step shoot in Handball. Methods: Nine elite adult handball players working in the Super League (23.55 ± 2.69 years) and ten teen handball players (16.4 ± 0.69 years) participated in this study. The pictures related to the final stage of the shoot were recorded three dimensionally and analyzed by a graphic interface in MATLAB software. The data related to the angular position, angular velocity and peak angular velocity and position corresponding to the upper limb joints of athletes, including the wrist, elbow and shoulder were obtained. Statistical data were used for analysis through student t-test for two independent groups with significance level p ≥ 0.05 in order to compare two groups. Findings: There were significant differences between two groups in angular position of elbow joint during extension at maximum angular velocity and linear velocity of the ball at the time of the release. Conclusion: it seems that other factors than cinematic characteristics such as anthropometric characteristics along with muscle strength in adult are important to get the maximum velocity of ball release.
Dr Mohammad Yousefi, Mr Hamidreza Zanguie,
Volume 20, Issue 24 (3-2023)
Abstract
Genovarum and Genovalgum are the most common postural deformities of the knee joint. A quadriceps angle is used to measure these anomalies. Methods of measuring this angle are divided into two categories: invasive and non-invasive. The purpose of the present research was to study the inter/intra rater reliability of the non-invasive Body Landmarks Analyzer method for measuring of the quadriceps angle. Seventeen males (Age: 23.40 ± 1.7 years, height: 176.32 ± 6.41 cm, weight: 72.25 ± 14.6 kg, and BMI: 22.33 ± 1.38, kg/m2). participated in this study. Body landmarks analyzer system consists of a pen (sender) and camera (receiver), both of which are equipped with IR sensors. Anatomical Landmarks of the ASIS, medial and lateral epicondyle, tibial tuberosity, and medial and lateral malleolus were used to diagnose and calculate the quadriceps angle position. Intra-class correlation coefficient (ICC) two-way mixed model on absolute agreement was used to identify the inter/intra raters’ reliability. The results showed that the intra-rater reliability for the first technician was 0.83; The second technician is 0.81 and the third technician is 0.8. In addition, the inter-rater reliability was also 0.85. Therefore, it can be stated that the Body Landmark Analyzer method has good reliability for use in the extraction of knee joint abnormalities. Therefore, it can be suggested that this system be used along with other non-invasive methods.
Nafise-Sadat Shahamiri, Dr Mohammad-Ali Soleiman-Fallah, Dr Foad Feizolahi,
Volume 20, Issue 24 (3-2023)
Abstract
The aim of this study is the effect of one period core stability exercise with and without kinesio taping on biomechanical effective factors in lower cross syndrome on female. 36 female between 30 to 40 were randomly divided in to 3 groups (control, with taping and without taping). each group consist 12 participant. To measure Pelvic slope, Hip and Knee ROM, Isometric strength of flexors and extensors, Abdominal muscle endurance, Flexibility of spine extensors, Endurance of core muscles, respectively was used Inclinometer, Goniometer, Dynamometer, Body flection test, Body straightening test and Planck test to the side. To evaluate research hypotheses, if there is a significant difference between them we was used analysis of covariance test and multiple comparison in averages with post hoc bonferroni test. The result of the survey indicate that difference between taping and control groups were significant in pelvic slope, hamstring and rectus femoris flexibility, knee and hip flexors muscle strength )p≥0/05(. Difference between without taping and control groups were significant in pelvic slope, rectus femoris and spine extensors flexibility (p≥0/05(. Difference between with and with¬out taping groups were significant in hamstring and iliopsoas flexibility, knee flexors, hip flexors, extensors, adductors strength, core muscles endurance )p≥0/05(. The results show that training with taping has an effective role on reducing lower cross syndrome. So it is suggested that taping can be used as an non-aggressive and low-cost method at the same time with exercise.
Ehsan Ebrahimipour, Fereshteh Sabet, Shayan Hajebrahimi, Mohammadreza Seyfaddini,
Volume 22, Issue 27 (8-2024)
Abstract
Circadian rhythms play a crucial role in regulating various physiological functions of the human body and can impact the ability tasks. The aim of this study was to investigate the effect of time of day on static and dynamic balance using the cognitive task approach. We recruited 24 elderly men who performed both static and dynamic balance tests with and without cognitive dual tasks. Our statistical analysis, using a significance level of 0.05, revealed significant differences in the parameters of the 95% confidence ellipse, length of path, and average velocity of the center of pressure when performing the dual task compared to normal walking. However, these variables did not significantly differ at different times of the day. Interestingly, our results showed that the center of pressure fluctuations in closed eyes and different times of the day did not have a significant difference. Overall, our findings suggest that healthy elderly individuals are at similar risk of falling during different hours of the day. Nonetheless, the simultaneous execution of dual cognitive tasks leads to balance disruption in both eyes-arm closed positions.
Amir Fatollahi, Amirali Jafarnezhadgero, Hamidreza Maghami,
Volume 22, Issue 27 (8-2024)
Abstract
Biomechanics is the knowledge that shows what forces enter the motion system of the human body and how it causes human movement. Therefore, the aim of this Meta-Analysis study was to review the studies conducted in the field of the effects of training on sand surface on biomechanics and physical fitness factors of human body during translational motions. The current study was a library and systematic review, the search for articles in Persian and Latin was from the beginning of the year 2000 to the end of 2023, which was done in the specialized databases of PubMed, WOS, Scopus, ISC and Google Scholar search engine. 568 related articles were selected based on inclusion and exclusion criteria. Standardized mean differences (SMDs) were calculated using random-effects models. The findings of eight articles indicated the improvement of mucle activity during training on sand. Examining the findings of one article indicated positive effects of kinematic variabls during training on sand. A number of two articles also reported that the reduction of the ground reaction forces and impact shock. In addition, five articles reported the improvement of sports performance in athletes, the increase of physical fitness factors. In general, training on sand surface can have significant positive effects on people's daily and sport life. Further study is warranted.
Saeed Arsham,
Volume 22, Issue 27 (8-2024)
Abstract
This study aimed to determine the underlying mechanisms of age-related differences in postural control of 7-18 years old girls by determining the differences between different age groups and adults in their sensory preferences for compensatory responses. 118 non-athlete girls aged 7 to 18 were selected by available sampling and divided into four age groups: 7-9 (n=31), 10-12 (n=32), 13-15 (n=28), and 16-18 (n=27). A reference group of adults (n=28, Mean= 27.9 years) was examined for comparison. Sensory organization test (SOT) with computerized dynamic posturography was used to manipulate sensory inputs. One-way analysis of variance and Tukey post hoc test showed a significant difference between all age groups in 6 test conditions (P<0.05). The use of somatosensory and vestibular sensory inputs to maintain balance was almost the same in different age groups, but significant differences were observed in the use of visual inputs. From the age of 13, the postural control performance of girls becomes similar to that of adults, which can be due to the delayed development of the visual system. In general, it seems that for perfect postural control, first the somatosensory sensory system and then the vestibular and visual systems mature.
Mohammadreza Rahimi, Neda Boroushak,
Volume 22, Issue 28 (12-2024)
Abstract
This study focuses on the design, construction, and validation of a digital-adjustable, weight-free home fitness device for muscle training. The research adopted a mixed-methods approach, providing a comprehensive evaluation of the device's performance. Initially, existing equipment and resistance training methods were analyzed, gathering essential information for the preliminary design. Three-dimensional models and prototypes were developed using software such as Rhino Cross 6 and AutoCAD 2018. For validation, the device’s resistance was tested with a digital dynamometer in eight different settings, yielding a high validity with a correlation coefficient of 0.9. The reliability of the device was also assessed across three exercises (seated leg extension, seated chest press, and seated biceps curl) with 10 kg weights, repeated five times, resulting in a reliability coefficient of 0.8. These results indicate the device's high accuracy and consistent resistance. With precise digital adjustments and the capability for varied strength exercises, this device enables users to conduct effective, high-quality workouts at home, contributing to muscle strengthening and improved fitness.
Mohamadjavad Razi, Hasan Modares, Zahra Shakeri Hosinabad,
Volume 23, Issue 29 (7-2025)
Abstract
Introduction and Objective: The COVID-19 pandemic and virtual learning may adversely affect students' musculoskeletal health and physical activity levels. This study aimed to investigate the impact of online education and prolonged sitting on musculoskeletal disorders (MSDs) and physical activity among university students.
Methods: In this descriptive study, 440 male and female students from Farhangian University, Yazd Branch, were selected as the sample. Standard Nordic Musculoskeletal Questionnaire (NMQ) and Beck Physical Activity Questionnaire were used for data collection. Data were analyzed using McNemar, Mann-Whitney U, and Spearman’s correlation tests at a significance level of 0.05.
Results: The prevalence of MSDs during the pandemic showed a significant increase compared to the pre-pandemic period (p<0.05). A significant correlation was observed between reduced physical activity and increased MSDs (p<0.05). Students who did not follow proper sitting postures had significant disorders in the neck (p<0.0001), shoulder (p=0.006), wrist (p=0.002), lower back (p=0.001), hip (p=0.01), and knee (p=0.001).
Conclusion: The findings suggest that quarantine conditions and virtual learning may exacerbate musculoskeletal problems and sedentary behavior among students. Promoting ergonomic practices and physical activity during pandemics is crucial.
Salar Hariri, Heydar Sadeghi, Amir Ghiamirad, Saeed Nikookheslat,
Volume 23, Issue 29 (7-2025)
Abstract
Background and Objective: Since identifying the best way of performing the Judan Mai-Mawashi-Geri technique is one of the concerns of coaches and karatekas, the aim of this study was to compare the selected kinematic variables of four methods of implementing the Judan Mai-Mawashi-Geri technique by elite male karatekas.
Methodology: Eighteen elite male kumite practitioners voluntarily and purposefully participated in this study. Nine markers were attached to the anatomical points of the hitting foot and the four methods of implementing the Judan Mai-Mawashi-Geri technique were filmed by three Hero3 cameras at an imaging speed of 240 Hz. Using SkillSpector software (version: 1.3.2), the resultant of the peak velocity of the lower limb joints, total distance, total velocity, and total acceleration was directly obtained. The one-way analysis of variance and the Bonferroni post-hoc test (p≤0.05) were used with SPSS software (version: 22) for statistical analysis due to the normality of data distribution.
Results: The results showed a significant difference in the four methods of performing the Judan Mai-Mawashi-Geri technique in the peak velocity of the pelvic, knee, and ankle joints as well as total distance, total velocity, and total acceleration.
Conclusion: According to the results، the first method of execution، which starts in the first phase with 90 degree hip flexion (knee lift)، due to high speed and the possibility of scoring in the shortest appropriate time interval، against other tactics, Due to the closure of the opponent's attack route، Dai and Deashi can be recommended as a more efficient technique to the Athlete of the Kumite.
Amirali Jafarnezhadgero, Arezoo Madahi, Milad Piran Hamlabadi,
Volume 23, Issue 29 (7-2025)
Abstract
Background and Aims: The surface quality and type are an important factor that may influence the risk of sustaining injuries during running. The aim of the present study was to compare forces excreted on the foot while running on the ground and artificial turf in people with pronated and supinated feet.
Materials and Methods: The statistical population of the present study consisted of healthy men with pronated and supinated feet in Ardabil province. A statistical sample of 30 people aged 20-25 years was selected by available sampling and participated in the present study. Statistical samples were divided into three groups. There were 10 patients in the pronated foot group, 10 people in the supinated foot group and the third group of 10 people as the control group. The navicular drop test was used to measure foot type. A Bertec force plate was used to record ground reaction forces while running on ground and artificial turf at constant speed (about 3.2 m/s). The ground reaction forces in the vertical (Fz), anterior-posterior (Fy) and medio-lateral (Fx) directions were recorded during running.
Results: The results revealed greater medio-lateral ground reaction force at the heel contact in males with pronated feet while running on the ground than that artificial grass. In addition, the time to reach the peak of the vertical component at heel contact during running on grass was greater compared to the ground.
Conclusion: The results showed that the use of artificial turf can improve the risk factors for injury in people with pronated and supinated feet.
Hamidreza Zanguie, Mohammad Yousefi, Abbas Farjadpezeshk, Khorshid Bijari,
Volume 23, Issue 29 (7-2025)
Abstract
Aim: Most studies have compared the single-leg landing task in terms of biomechanical characteristics, especially kinematics and kinetics of movement planes, and concluded that reliability for knee valgus angles and hip adduction is moderate to excellent. However, no studies have been conducted on the reliability of different types of single-leg landing. Therefore, the purpose of this study is to review studies investigated the reliability of single-leg landing types to evaluate the biomechanics of the knee joint.
Methods: The relevant articles from valid databases with the keywords Single Leg Landing, Landing, Kinematic, Biomechanics, Return to Sport, Performance Test, Functional Test, Hop Test, Kinetic thematic search methods from 1995 to 2023 were examined.
Result: A total of 1022 articles were identified then duplicate studies were eliminated in the next stage, the titles and abstracts of the studies were reviewed and 439 studies were excluded due to inconsistency with the research question. Finally, only 9 articles that met the inclusion criteria were examined.
Conclusion: This study showed that different single-leg landing tasks for kinematic variables, including internal rotation, adduction, hip flexion, knee extension, knee valgus, trunk lateral flexion, and pelvic tilt have good reliability.
Masume Fadaei, Mehrdad Anbarian,
Volume 23, Issue 30 (1-2026)
Abstract
Background and Aims: The purpose of this study was to evaluate the effect of quadriceps muscle fatigue on electromyographic activity of selected lower limb muscles during lifting loads using different techniques.
Methods: Surface electromyography activity of the rectus femoris, vastus latralis, vastus medialis, biceps femoris, semitendinous, gastrocnemius medialis and tibialis anterior muscles of 20 able-bodied women were recorded before and after the quadriceps muscle fatigue using leg-press movement, squat, stoop and strudel techniques with 20% of body weight. Analysis of Variance with repeated measures was used for data analyses (p<0.05).
Results: After fatigue when lifting the load, the activity of the rectus femoris, vastus medialis, biceps femoris and gastrocnemius medialis in squat and stoop techniques was significantly different compared to before fatigue condition. But no significant difference was observed between the activity of any of the muscles before and after fatigue in the straddle method.
Conclusion: According to the results, it seems that when quadriceps muscle fatigue, the use of straddle technique to lift the load is more appropriate.
Saeed Mollahoseini Paghale, Milad Fallahzade, Mohammadreza Amirseyfadini,
Volume 23, Issue 30 (1-2026)
Abstract
Background and Aims: Controlling hand tremors in neurological disorders like Parkinson's has gotten a lot of attention in recent decades. The number of theories about closed-loop deep brain stimulation is rapidly growing. The goal of this work is to offer a machine learning-based automated closed loop system for the rehabilitation of Parkinson's patients with hand tremor symptoms.
Materials and Methods: In the current study, vibration was simulated using a mathematical model that included a muscle model, basal ganglia, cortex, and supplementary motor area. To manage hand tremor, the non-integer PID proportional controller, as well as the intelligent Proximal Policy Optimization (PPO) algorithm as a subset of reinforcement learning, are employed to adapt the coefficients.
Results: One of the advantages of the proposed method, aside from reducing hand tremor and automatic learning to use at various levels of the disease, which has yielded acceptable results when compared to other control methods, is its practical implementation in the real world due to the simplicity of the controller. The automatic adjustment of artificial intelligence network coefficients in the presented strategy (PPO) makes it simple to create intelligent system.
Conclusion: The proposed intelligent system significantly reduces the side effects of continuous brain stimulation in the open-loop manner stimulation, in addition to optimizing output signals such as hand tremor compared to other controllers and being usable for all levels of the disease due to its adaptability.
Mohsen Barghamadi, Roghayeh Parsa, Amir Fatollahi,
Volume 23, Issue 30 (1-2026)
Abstract
Background and Aims: Volleyball players apply force at short speed more oblique strokes to the ball so that it lands quickly on the ground.The aim of the present study is to compare the effects of two types of resistance training with cable and barbells on vertical force and impulse caused by oblique strokes in the spike of female volleyball.
Materials and Methods: The present study method was semi-experimental. The statistical population of this study included 45 female volleyball players from Mohaghegh University. The statistical samples was divided into three groups of 15 people in the training groups 1 with barbell, dumbbell, medicine training tools, and groups 2 with training with cable bodybulding equipment, and the third group in as control group. Force plate was used to record ground reaction forces.The table was used to adjust the height diagonal shots, the invisible string and the volleyball ball for the dominant hand shot volleyball players.
Results: The effects of the force resulting from the diagonal impact on the ball on the vertical ground reaction force were significant in the group1 (p< 0.008) and not significant in group 2 (p< 0.133).The effect of the impulse time factor in the strength training group on the vertical component of the ground reaction force was significant in group1 (P<0.030) and in group 2 (P<0.023).
Conclusion: combined strength training with barbell and medicine increases power in diagonal shots and produces maximum vertical force in a shorter time to the ball in diagonal spike shots in volleyball.
