Musculoskeletal Systems Modeling
Elham Hazrati; Mahmoud Reza Azghani
Volume 11, Issue 1 , May 2017, , Pages 19-28
Abstract
Pedaling is one of the common physical activities for muscles strengthening. Pedaling performance is affected by various factors. The purpose of this study is investigating the effect of pedaling rate and resistance moment against pedaling in the feasible pedaling places (kinematics view) on the muscles ...
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Pedaling is one of the common physical activities for muscles strengthening. Pedaling performance is affected by various factors. The purpose of this study is investigating the effect of pedaling rate and resistance moment against pedaling in the feasible pedaling places (kinematics view) on the muscles activity and ankle, knee and hip joints forces. For this purpose, the biomechanical model of human movement system presented in AnyBody software, is used. The mechanical power of pedaling is deemed to constant (200 w). The Pedaling rate of 40, 60, 80, 100 and 120 rpm and the resistance moment of 0, 5, 10, 15 and 20 Nm, are considered in the pedaling feasible places. Results indicate that although the range of pedaling feasible places is proper by the kinematics view, however changing the pedaling rate and the applied resistance moment, all of the pedaling places from this range cannot be proper due to the excessive muscles activity (more than 0.95). In the pedaling rate of 80, 100 and 120 rpm by applying the resistance moment of 0 and 5 Nm, approximately all of the feasible places are suitable (muscles activity are less than 0.95). By increasing the pedaling rate in a constant resistance moment, the large part and reversely, by increasing the resistance moment in a constant pedaling rate, the small part of feasible range are appropriate. Joints forces increase with decreasing the pedaling rate and increasing the applied resistance moment.
Biomechanics of Bone / Bone Biomechanics
Mahmoud Reza Azghani; Sharareh Kian-Bostanabad; Tara Ahmadi; Hamid Khabiri
Volume 10, Issue 4 , January 2017, , Pages 339-346
Abstract
Long bone fracture is the most prevalent traumatic fractures that accures due to the strike and attacted load exertions, which one of them is the butterfly fracture. This type of fracture may happen with sudden and combined forces. Since in this type of fracture, the number of fracture lines is more ...
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Long bone fracture is the most prevalent traumatic fractures that accures due to the strike and attacted load exertions, which one of them is the butterfly fracture. This type of fracture may happen with sudden and combined forces. Since in this type of fracture, the number of fracture lines is more than other types of fractures, developing a prohibitive method may be usfull. The present paper is aimed to investigate the effects of strain rate and use of fastener on butterfly fracture in bone samples. To this end, invivo sheep metacarpal bone samples were examined in four groups: distinguished based on different strain rates, loading conditions and boundry conditions. The first one underwent pure bending at rate of 20 mm/s. The second group and third group experience combined bending and axial compression at rate of 5 mm/s and 20 mm/s, respectively. Bone samples in the fourth group, however, sustained combined loading of bending and axial compression while their ends had been fixed. Comparison between the first and third groups significantly stated that exerting axial compression increases the number of butterfly fractured samples. Results show that at the higher strain rates, the number of butterfly fracture increases. Constraining the ends of the bone samples, on the other hand, led to dissipate the effects of combined loading and also high strain rate. Furthermore, a considerable accordance was observed based on Pearson Correlation test by amount of 0.947.
Musculoskeletal Systems Modeling
Sharareh Kian-Bostanabad; Mahmoud Reza Azghani; Leila Rahnama
Volume 9, Issue 3 , December 2015, , Pages 283-291
Abstract
Cervical multifidus muscle is one of the neck extensor muscles that plays an important role in the neck stability. By observing the different behaviors for this muscle during the six shoulder activities in previous study, it was modeled within the software and the effect of its action on the different ...
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Cervical multifidus muscle is one of the neck extensor muscles that plays an important role in the neck stability. By observing the different behaviors for this muscle during the six shoulder activities in previous study, it was modeled within the software and the effect of its action on the different shoulder activities evaluated as a parametric study. For this end, a biomechanical model of the human locomotion system, which includes muscles of the shoulder, forearm and hand and 3 joints, was considered. After finding the maximum strength in six movement directions of the shoulder joint including flexion, extension, internal rotation, external rotation, abduction and adduction, the strength of 0, 25, 50, 75 and 100 percent of the maximum strength applied to model for each activities separately and the percentage of cervical multifidus and shoulder muscles activities have been saved. Moreover, applied torques by these muscles during different activities have been measured by calculating their effective torque arm. Assesing the relationship between the strength of cervical multifidus muscle with contraction level using the regression models showed a high correlation between these two factors during abduction, external rotation and extension activities (R2= 0.96-0.997). The produced torque by this muscle is more than the main muscles during the abduction and external rotation activities. This study showed that cervical multifidus muscle disfunction in addition to effect on the range of motion of neck, can be effective on the shoulder joint activities that it should be considerd in NIOSH lifting equation for individuals with neck pain.
Biomedical Image Processing / Medical Image Processing
Sharare Kian-Bostanabad; Mahmoud Reza Azghani; Leila Rahnama
Volume 9, Issue 4 , February 2015, , Pages 341-350
Abstract
The cervical multifidus muscle is known as one of the deep neck extensor muscles that its dysfunction have been reported in people with neck pain.With regard to the limits on the evaluation of this muscle activity using electromyography, ultrasound was used to find out its function recently. The aim ...
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The cervical multifidus muscle is known as one of the deep neck extensor muscles that its dysfunction have been reported in people with neck pain.With regard to the limits on the evaluation of this muscle activity using electromyography, ultrasound was used to find out its function recently. The aim of this study is evaluation of this muscle dimansions change during six shoulder joint activities in healthy subjects and people with chronic neck pain and providing predictive models. So The relationship between strength of shoulder joint during contraction with the changes of anterior-posterior dimension, lateral dimension, shape ratio and size of the cervical multifidus muscle were assessed using of Response Surface Method in the first step for subjects and activities and then for activities with subject blocking. Finally, predictive models were provided for abduction activity in 0-50% of maximum voluntary contraction (MVC) for healthy subjects and 50-100% for patients with data clustering. The anterior-posterior dimension showed a higher correlation with the shoulder joint strength than other factors. R2 values for this dimension in healthy subjects before and after data clustering is 0.552 and 0.66 and in patients is 0.339 and 0.505 respectively. Given the models correlation coefficient and its enhance by data clustering, it seems that evaluation of anterior-posterior dimension of this muscle during isometric abduction activiy of shoulder joint with the sttrength of 0-50% MVC for healthy subjects and 50-100% for patients with neck pain can be provide useful information about its function.
