Search for: biomechanical-phenomena
Total 47 records
Role and significance of trunk and upper extremity muscles in walker-assisted paraplegic gait: a case study, Article Topics in Spinal Cord Injury Rehabilitation ; Volume 24, Issue 1 , 2018 , Pages 18-27 ; 10820744 (ISSN) ; Farahmand, F ; Arazpour, M ; Zohoor, H ; Sharif University of Technology
Thomas Land Publishers Inc 2018
Background and Purpose: Understanding the role and significance of trunk and upper extremity muscles in paraplegic gait can help in designing more effective assistive devices for these patients and also provides valuable information for improving muscle strengthening programs. Methods: In a patient with a spinal cord injury (SCI) who could walk independently (rating scale of ambulatory capacity, 9) with the aid of bilateral ankle-foot orthosis and a walker, the kinematics, kinetics and electromyographic (EMG) activities of 16 muscles from the trunk and upper and lower extremities were recorded during gait. The onset, cessation, and duration of the EMG signal were associated with the 4 phases...
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
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...
A comprehensive approach for the validation of lumbar spine finite element models investigating post-fusion adjacent segment effects, Article Journal of Biomechanics ; Volume 121 , 2021 ; 00219290 (ISSN) ; Arjmand, N ; Sharif University of Technology
Elsevier Ltd 2021
Spinal fusion surgery is usually followed by accelerated degenerative changes in the unfused segments above and below the treated segment(s), i.e., adjacent segment disease (ASD). While a number of risk factors for ASD have been suggested, its exact pathogenesis remains to be identified. Finite element (FE) models are indispensable tools to investigate mechanical effects of fusion surgeries on post-fusion changes in the adjacent segment kinematics and kinetics. Existing modeling studies validate only their intact FE model against in vitro data and subsequently simulate post-fusion in vivo conditions. The present study provides a novel approach for the comprehensive validation of a lumbar...
The effects of movement speed on kinematic variability and dynamic stability of the trunk in healthy individuals and low back pain patients, Article Clinical Biomechanics ; Volume 30, Issue 7 , Aug , 2015 , Pages 682-688 ; 02680033 (ISSN) ; Sanjari, M. A ; Mokhtarinia, H. R ; Moeini Sedeh, S ; Khalaf, K ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd 2015
Background: Comparison of the kinematic variability and dynamic stability of the trunk between healthy and low back pain patient groups can contribute to gaining valuable information about the movement patterns and neuromotor strategies involved in various movement tasks. Methods: Fourteen chronic low back pain patients with mild symptoms and twelve healthy male volunteers performed repeated trunk flexion-extension movements in the sagittal plane at three different speeds: 20 cycles/min, self-selected, and 40 cycles/min. Mean standard deviations, coefficient of variation and variance ratio as variability measures; maximum finite-time Lyapunov exponents and maximum Floquet multipliers as...
Relative performances of artificial neural network and regression mapping tools in evaluation of spinal loads and muscle forces during static lifting, Article Journal of Biomechanics ; Volume 46, Issue 8 , 2013 , Pages 1454-1462 ; 00219290 (ISSN) ; Ekrami, O ; Shirazi Adl, A ; Plamondon, A ; Parnianpour, M ; Sharif University of Technology
Two artificial neural networks (ANNs) are constructed, trained, and tested to map inputs of a complex trunk finite element (FE) model to its outputs for spinal loads and muscle forces. Five input variables (thorax flexion angle, load magnitude, its anterior and lateral positions, load handling technique, i.e., one- or two-handed static lifting) and four model outputs (L4-L5 and L5-S1 disc compression and anterior-posterior shear forces) for spinal loads and 76 model outputs (forces in individual trunk muscles) are considered. Moreover, full quadratic regression equations mapping input-outputs of the model developed here for muscle forces and previously for spine loads are used to compare the...
Design, construction, and evaluation of “sensor lock”: an electromechanical stance control knee joint, Article Disability and Rehabilitation: Assistive Technology ; Volume 13, Issue 3 , 2018 , Pages 226-233 ; 17483107 (ISSN) ; Ahmadi Bani, M ; Baniasad, M ; Samadian, M ; Golchin, N ; Sharif University of Technology
Taylor and Francis Ltd 2018
Background and aim: Most currently-available stance control knee ankle foot orthoses (SCKAFOs) still need full knee extension to lock the knee joint, and they are still noisy, bulky, and heavy. Therefore, the aim of this study was to design, construct, and evaluate an original electromechanical SCKAFO knee joint that could feasibly solve these problems, and thus address the problems of current stance control knee joints with regards to their structure, function, cosmesis, and cost. Method: Ten able-bodied (AB) participants and two (knee ankle foot orthosis) KAFO users were recruited to participate in the study. A custom SCKAFO with the same set of components was constructed for each...
The influence of new reciprocating link medial linkage orthosis on walking and independence in a spinal cord injury patient, Article Spinal Cord ; Volume 53 , October , 2015 , Pages S10-S12 ; 13624393 (ISSN) ; Arazpour, M ; Farahmand, F ; Azmand, A ; Hutchins, S. W ; Vahab Kashani, R ; Mousavi, M. E ; Sharif University of Technology
Nature Publishing Group 2015
Objectives: The purpose of this paper is to describe the development and evaluation of a new medial linkage reciprocating gait orthosis (MLRGO) that incorporates a reciprocal mechanism and is sensitive to pelvic motion to potentially assist paraplegic patients to walk and provide functional independence. Case description and methods: The new orthosis was constructed and tested by a 20-year-old female paraplegic subject with transverse myelitis at T10 level, who was 4 years post injury and had also been an isocentric reciprocating gait orthosis (IRGO) user for 2 years. She received gait training for 12 weeks before undertaking gait analysis, and also completed a questionnaire that was...