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A Biomechanical Model for Evaluation of Shoulder Function: Detecting the
Relationship Between Muscles Activation Patterns and Shoulder Joint Torques Using Synergy Concept
,
M.Sc. Thesis
Sharif University of Technology
;
Parnianpour, Mohamad
(Supervisor)
;
Asghari, Mohsen
(Supervisor)
Abstract
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...
Shoulder Wearable Rehabilitation Exoskeleton Optimal Design
, M.Sc. Thesis Sharif University of Technology ; Sohrabpour, Saeed (Supervisor) ; Zohoor, Hassan (Co-Advisor)
Abstract
Rehabilitation usually involves physical therapy, occupational therapy and counseling for the patient's morale to help to restore his power and performance. Considering the economic outlook and the costs of rehabilitation methods and due to the increasing prevalence of stroke and the need to recover the patients in a short period, only the use of robotic systems opens the door to the medical community. Since a large rehabilitation robots designed and built and each been used according to their advantages and shortcomings. In this project, the major shortcomings examined and exoskeleton designed on two major features including portability and covering shoulder workspace. Shoulder movement was...
Effect of Hand-Held Flexible-Bar on Postural Stability and Shoulder Muscle Synergies during Repetitive Planar Hand Exercises
, M.Sc. Thesis Sharif University of Technology ; Parnianpour, Mohammad (Supervisor) ; Hoviattalab, Maryam (Supervisor)
Abstract
Shoulder is one of the most important joints of the body with high degrees of freedom. Synergic analysis of the shoulder muscles shows the joint condition due to applied force or torque. The results of the linear COP parameters and nonlinear analysis indicate the characteristics of subjects postural stability. The flexi-bar is a rehabilitation tool which stimulates the muscles. In this study, the effect of bar on the body has been examined. The modeling is carried out in two horizontal and vertical condition of bar in sixteen separate positions in the upper right side quadrant of the model. Muscle activation and joint stiffness, force and torque were obtained. COP data in AP and ML were...
How well do the muscular synergies extracted via non-negative matrix factorisation explain the variation of torque at shoulder joint?
, Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 16, Issue 3 , 2013 , Pages 291-301 ; 10255842 (ISSN) ; Aminian, K ; Asghari, M ; Parnianpour, M ; Sharif University of Technology
2013
Abstract
The way central nervous system manages the excess degrees of freedom to solve kinetic redundancy of musculoskeletal system remains an open question. In this study, we utilise the concept of synergy formation as a simplifying control strategy to find the muscle recruitment based on summation of identified muscle synergies to balance the biomechanical demands (biaxial external torque) during an isometric shoulder task. A numerical optimisation-based shoulder model was used to obtain muscle activation levels when a biaxial external isometric torque is imposed at the shoulder glenohumeral joint. In the numerical simulations, 12 different shoulder torque vectors in the transverse plane are...
Muscle synergies based on a biomechanical biaxial isometric shoulder model minimizing fatigue
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010 ; Volume 1 , 2010 , Pages 797-804 ; 9780791849156 (ISBN) ; Aminian, K ; Asghari, M ; Parnianpour, M ; Sharif University of Technology
Abstract
In this study we utilize the concept of synergy formation as a simplifying control strategy to manage the high number of degrees of freedom presented in the maintenance of the posture of the shoulder joint. We address how to find the muscle synergy recruitment map to the biomechanical demands (biaxial external torque) during an isometric shoulder task. We use a numerical optimization based shoulder model to obtain muscle activation levels when a biaxial external isometric torque is exposed at the shoulder glenohumeral joint. In the numerical simulations, different shoulder torque vectors parallel to the horizontal plane are considered. For each selected direction for the torque, the...
Objective measurement of inferior-directed stiffness in glenohumeral joint using a specially designed robotic device in healthy shoulders; within- and between-session reliability
, Article Journal of Biomechanics ; Volume 127 , 2021 ; 00219290 (ISSN) ; Mirbagheri, A. R ; Hosseini, R ; Shadmehr, A ; Karimi, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Clinical assessment of capsuloligamentous structures of the glenohumeral joint has been qualitative and subjective in nature, as demonstrated by limited intra- and inter-rater reliability. Robotic devices were utilized to develop a clinically objective measurement technique for glenohumeral joint stiffness. The purpose of this study was to quantify the amount of inferior-direction stiffness of the glenohumeral joint using a safe clinical device in the asymptomatic individuals, and to determine between trial and between session reliability of the robotic device. Twenty healthy subjects were recruited via convenience sampling. Inferior-directed translation and applying force were measured...