Sharif Digital Repository

The purpose of this project is to design and build a motorized walker with sit to stand ability, by means of which the user can get up from a chair or the edge of the bed and stand with complete independence; Relying on it, the patient could walk easily and finally sit down on the chair, the edge of the bed, or the toilet seat. For this purpose, the conducted researches and previously built devices were studied and the strengths and weaknesses of each were examined. The stages of conceptual design including the design of the sit to stand mechanism, the design of the structure and finally the control algorithm were completed, then the detailed design of the mentioned topics was carried out.... 

Low back pain (LBP), the leading cause of disability worldwide, remains one of the most common and challenging occupational musculoskeletal disorders. The effective assessment of LBP injury risk, and the design of appropriate treatment modalities and rehabilitation protocols, require accurate estimation of the mechanical spinal loads during different activities. This study aimed to: 1) develop a novel 2D beam-column finite element control-based model of the lumbar spine and compare its predictions for muscle forces and spinal loads to those resulting from a geometrically-matched equilibrium-based model; 2) test, using the foregoing control-based finite element model, the validity of the... 

Torsional misalignment of lower extremities is a bone deformity of femur, tibia, knee twist or a complex of all these factors. These deformities affect the patient's gait kinematics. These patients are usually treated with osteotomy surgery with the aim of correction of anatomy. But it doesn't necessarily lead to the modification of gait. Therefor development and application of subject-specific musculoskeletal models to analyze patient's specific condition and predict corrective surgery results are considered. Accordingly, the aim of this project is to create a subject-specific musculoskeletal model for a patient with femoral anteversion in order to predict result of anatomical correction... 

Posterior lumbar surgery is often associated with extensive injuries to back muscles. In this thesis, the effect of such iatrogenic injuries in some patients was examined. For this purpose, the CSA of back muscles in 6 patients were measured using MR scan. To examine any natural change in CSAs of healthy people or instrument errors, same measurement were carried out on 10 healthy volunteers. In addition, a detailed anatomical model of an intact human spine was developed. With the aim of experimental studies and intact model, the post-operative model of patients was also developed. These two models were used to quantizing the change in activity of back muscles during some symmetric, normal... 

Spine is one of the most important musculoskeletal systems of the human body. Any problem which is related to this part of human body causes pain and disability. Spinal compression forces are one of the main reasons of this disability and pain. It is assumed that intra-abdominal pressure causes spinal unloading in lifting. Studies usually don’t consider the role of intra-abdominal pressure and introduce it as an effective parameter which can increases spinal stability and influences spinal mechanics.Generation mechanism of intra-abdominal pressure remain enigmatic, studies that advocate the unloading effect of IAP usually consider a raise in IAP to be primarily due to the activity of... 

One of the most common diseases associated with musculo-skeletal ailment is low back pain which is epidemic among general public so that billions of dollars is spent annually to treat this disease. There are back pain prevention strategies include training on correct lifting, ergonomic tool design, and industrial automation amongst others. In recent years, assistive devices have also been used to prevent back pain. There are assistive devices that can be installed on the body and significantly have reduced forces required for Erector Spinae muscle and Lumbar moments. In this research, at first the anatomy of the spine and muscles and method of processing Electromyography (EMG) of muscles... 

The effects of combined task demands on the way muscles are recruited to balance external loads during posture and movement is of great importance in quantitative analysis of upper arm function. Pain and disability of shoulder joint is becoming more important as population spends more often interacting with computers in seated position and carrying repetitive tasks using upper extremities. Shoulder joint that is more dependent on the muscles for its normal function than other joints such as hip due to its small articular surface and large range motion has been used here to study its coordination during isometric exertions. Since, the numbers of tasks that could be performed are enormous. In...