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Goran Abdulrahman Mohammed

Bio: Goran Abdulrahman Mohammed is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

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Dissertation
01 Jan 2017
TL;DR: The developed musculoskeletal system model is linearized in order to have clear stability analysis using Routh-Hurwitz stability criterion and eigenvalue analysis and reveals how the sway range (sway points) depends on the used anatomical and anthropometry data.
Abstract: Human body upright standing is inherently unstable, and as a bipedal creature, the body can implement several functions such as upright standing, walking and running, with the help of the central nervous system. Understanding the stability control of the human body during upright standing is important for prosthetic design and joint prostheses, walking restoration, diagnosis of nervous system diseases. Also, it is essential to anthropology, clinical research, aerospace science and kinesiology. Therefore, the objective of this work is to model the musculoskeletal system of human upright standing posture for analysis and control design of body sway. An asymmetric Gaussian function is proposed to model the force-length relationship and compared with other existing force-length models. By using least square curve fitting tools with a set of rabbit experimental data, and simulated data that represent sarcomere of the frog. Also, the implicit and explicit ordinary differential equations, are used to model muscle-tendon unit and compare the simulation results in term of singularity. In addition to, the equilibrium analysis is used to determine sway ranges during upright standing, and the equilibrium points can be used to linearize the model for feedback control design and stability analysis of the musculoskeletal system. Furthermore, a switching function is designed to model the intermittent activity of the MG muscle, where the parameters are optimised using the centre of gravity and electromyography data with Genetic Algorithm tool. The musculoskeletal system of the human body is modelled as a single inverted pendulum, which rotates around the ankle joint, in the sagittal plane only. The calf muscles especially the medial gastrocnemius activated intermittently, and soleus activated continuously are included in the model of the musculoskeletal system. The developed musculoskeletal system model is linearized in order to have clear stability analysis using Routh-Hurwitz stability criterion and eigenvalue analysis. The results show that the musculoskeletal system cannot be stabilised at the upright standing without feeding back angular velocity. The equilibrium analysis reveals how the sway range (sway points) depends on the used anatomical and anthropometry data. Finally, the stability analysis shows that during forwarding sway the calf muscles are shortening paradoxically and lengthening during backwards sway, which supports some existing experimental results. The model-based analysis which used in modelling the body upright standing, will help in analysis and understands the dynamics of the body during upright standing. Also, it assists in medical research, in clinical diagnostics and application.

2 citations


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TL;DR: You could look for impressive publication by the title of Basic Biomechanics Of The Musculoskeletal System by panamabustickets.com Studio to aid you obtain originality about the book you check out.
Abstract: You could look for impressive publication by the title of Basic Biomechanics Of The Musculoskeletal System by panamabustickets.com Studio Presently, you can conveniently to review every publication by online and download without spending great deals time for seeing book stores. Your best publication's title is here! You can discover your book to aid you obtain originality about the book you check out. Locate them in zip, txt, word, rar, kindle, ppt, and pdf report. basic biomechanics mccc basic biomechanics “it is important when learning about how the body moves (kinesiology) to also learn about the forces placed on the body that cause the movement.” lippert, p93

532 citations

Dissertation
01 Jan 2014
TL;DR: The model derived and analysed explains that the human body was able to maintain its upright posture mechanically during unperturbed quiet standing without the use of an active control system emphasising the importance of damping and its influence on postural balance.
Abstract: This study derives an inverted pendulum model for quiet stance in humans around the ankle joints with 4×9-element mass-spring-damper (MSD) units as the musculoskeletal connections between the shank and foot bilaterally. The model focuses on the role played by both the stiffness and the damping parameters of muscles, tendons and ligaments about the ankle complex. This model partitions muscles, tendons and ligaments functionally. This novel model is used to study the behaviour of individual components in relation to quiet standing. The Lagrange d’ Alembert principle has been used to derive the equations of motion of the system and resulted in eighteen 2nd order differential equations with nine constraints. Four MSD units connects with the shank (tibia and fibula) and foot bilaterally. The units function passively and are representative of the mechanical functionality of muscles, tendons, and ligaments about the ankle complex. The dynamics of the MSD units are considered linear in nature and their stiffness and damping parameters are calculated by finding the slope of the force vs. deformation length curve and force vs. velocity curve reported in the literature. The simulation results revealed that the torques generated by the internal constraints through the MSD units are significantly greater than the gravitational torque. A case study has been conducted for eyes open vs. eyes closed conditions. It was found that the angular displacement of the shank varied but the overall range of motion of the ankle joint remained constant at 0.6◦. This was expected as there was no external perturbation applied to facilitate any amount of plantarflexion or dorsiflexion at the point of articulation of the ankle joint. In conclusion, the model derived and analysed in this study explains that the human body was able to maintain its upright posture mechanically during unperturbed quiet standing without the use of an active control system emphasising the importance of damping and its influence on postural balance. Furthermore, this sophisticated model is not limited to only considering the muscle-tendon unit and ligaments play an important role in maintaining balance during quiet stance and are therefore included in the model. This model is physiologically more realistic than previously developed postural models thus providing a deeper insight towards the passive mechanism of postural balance and providing a new approach towards future postural models.

3 citations