Sharif Digital Repository

Games and their use in rehabilitation have formed a new and rapidly growing area of research. A critical hardware component of rehabilitation programs is the input device that measures the patients' movements. After Microsoft released Kinect, extensive research has been initiated on its applications as an input device for rehabilitation. However, since most of the works in this area rely on a qualitative determination of the joints' movements rather than an accurate quantitative one, detailed analysis of patients' movements is hindered. The aim of this article is to determine the accuracy of the Kinect's joint tracking. To fulfill this task, a model of upper body was fabricated. The... 

Background: Patients who have shoulder pain usually have compensatory or contributory deviation of shoulder motion during arm elevation. In the traditional scapulohumeral rhythm, the share of the acromioclavicular (AC) and the sternoclavicular (SC) joint movements and also the role of AC internal rotation angle are unknown. Objectives: The main purpose of this study was to measure and compare the segmentary scapulohumeral rhythm (SSHR) during scapular arm elevation at a steady rotational speed in athletes with and without impingement syndrome. Patients and Methods: Using a speedometer, the maximum speed of arm elevation was measured in 21 men in each of the involved and uninvolved groups.... 

Background The ratio of total lumbar rotation over pelvic rotation (lumbopelvic rhythm) during trunk sagittal movement is essential to evaluate spinal loads and discriminate between low back pain and asymptomatic population. Methods Angular rotations of the pelvis and lumbar spine as well as their sagittal rhythm during forward flexion and backward extension in upright standing of eight asymptomatic males are measured using an inertial tracking device. The effect of variations in the lumbopelvic ratio during trunk flexion on spinal loads is quantified using a detailed musculoskeletal model. Findings The mean of peak voluntary flexion rotations of the thorax, pelvis, and lumbar was 121 (SD... 

A safe rehabilitation exercise for anterior cruciate ligament (ACL) injuries needs to be compatible with the normal knee arthrokinematics to avoid abnormal loading on the joint structures. The objective of this study was to measure the amount of the anterior tibial translation (ATT) of the ACL-deficient knees during selective open and closed kinetic chain exercises. The intact and injured knees of fourteen male subjects with unilateral ACL injury were imaged using uniplanar fluoroscopy, while the subjects performed forward lunge and unloaded/loaded open kinetic knee extension exercises. The ATTs were measured from fluoroscopic images, as the distance between the tibial and femoral reference... 

The purpose of this work is to develop a computational model to describe the task of sit to stand (STS). STS is an important movement skill which is frequently performed in human daily activities, but has rarely been studied from the perspective of optimization principles. In this study, we compared the recorded trajectories of STS with the trajectories generated by several conventional optimization-based models (i.e., minimum torque, minimum torque change and kinetic energy cost models) and also with the trajectories produced by a novel multi-phase cost model (MPCM). In the MPCM, we suggested that any complex task, such as STS, is decomposable into successive motion phases, so that each... 

Image based registration of rigid objects has been frequently addressed in the literature to obtain an object's motion parameters. In this paper, a new approach of joint segmentation-rigid registration, within the variational framework of the phase field approximation of the Mumford-Shah's functional, is proposed. The defined functional consists of two Mumford-Shah equations, extracting the discontinuity set of the reference and target images due to a rigid spatial transformation. Multiscale minimization of the proposed functional after finite element discretization provided a sub-pixel, robust algorithm for edge extraction as well as edge based rigid registration. The implementation... 

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... 

Objective: The purpose of this study was to compare the relative stiffness of four common external fixation (XF) configurations used to span and stabilize the knee after knee dislocation. Methods: Synthetic composite femora and tibiae connected with cords were used to simulate a knee. Four configurations of external fixation were tested: anterior femoral pins with monotube (XF1), anterolateral femoral pins with monotube (XF2), anterolateral femoral pins with two connecting rods (XF3), and hinged ring fixator (XF4). Six specimens of each configuration were loaded nondestructively in varus/valgus, anterior-to- posterior shear, flexion/extension, axial compression, internal/external torsion,... 

Background: Studying the kinematics of the ACL deficient (ACLD) knees, during different physiological activities and muscle contraction patterns, can improve our understanding of the joint's altered biomechanics due to ACL deficiency as well as the efficacy and safety of the rehabilitations exercises. Methods: Twenty-five male volunteers, including 11 normal and 14 unilateral ACLD subjects, participated in this study. The kinematics of the injured knees of the ACLD subjects was compared with their intact knees and the healthy group during passive flexion and isometric leg press with the knees flexed from full extension to 45° flexion, with 15° intervals. An accurate registration algorithm... 

Range of motion (ROM) of the thoracic spine has implications in patient discrimination for diagnostic purposes and in biomechanical models for predictions of spinal loads. Few previous studies have reported quite different thoracic ROMs. Total (T1-T12), lower (T5-T12) and upper (T1-T5) thoracic, lumbar (T12-S1), pelvis, and entire trunk (T1) ROMs were measured using an inertial tracking device as asymptomatic subjects flexed forward from their neutral upright position to full forward flexion. Correlations between body height and the ROMs were conducted. An effect of measurement errors of the trunk flexion (T1) on the model-predicted spinal loads was investigated. Mean of peak voluntary total... 

Background: The use of knee-ankle-foot orthoses with drop locked knee joints produces some limitations for walking in subjects with quadriceps muscle weakness. The development of stance control orthoses can potentially improve their functionality. Objectives: The aim of this review was to compare the evidence of the effect of stance control orthoses to knee-ankle-foot orthoses with drop locked knee joints in improving kinematic variables and energy efficiency of walking by subjects with quadriceps muscle weakness caused by different pathologies. Study design: Literature review. Methods: Based on selected keywords and their composition, a search was performed in Google Scholar, PubMed,... 

In this paper design and fabrication of a wrist exoskeleton robot (ROBOWRIST) has been discussed. The robot has 3 degree of freedom, including flexion/extension, abduction/ adduction and pronation/supination based on the anatomical axis of the body. Four stepper motors are responsible for creating the motion. The exoskeleton can be used for neurorehabilitation and also post-surgery of wrist and forearm. Various therapeutic procedures with a precise tracking can be handled using the control algorithms. Each motor has a separate encoder to measure the angular position and send feedback to the controller. The design goal is to construct a reliable robot that is robust and applicable for... 

In this research, the nonlinear elastic behavior of human extensor apparatus was investigated. To this goal, firstly the best material parameters of hyperelastic strain energy density functions consisting of the Mooney–Rivlin, Ogden, invariants, and general exponential models were derived for the simple tension experimental data. Due to the significance of stress response in other deformation modes of nonlinear models, the calculated parameters were used to study the pure shear and balance biaxial tension behavior of the extensor apparatus. The results indicated that the Mooney–Rivlin model predicts an unstable behavior in the balance biaxial deformation of the extensor apparatus, while the... 

Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading;... 

Ligaments assist trunk muscles in balancing external moments and providing spinal stability. In absence of the personalized material properties for ligaments, finite element (FE) models use dispersed data from the literature. This study aims to investigate the relative effects of eight different ligament property datasets on FE model responses. Eight L4-L5 models distinct only in ligament properties were constructed and loaded under moment (15. N. m) alone or combined with a compressive follower load (FL). Range of motions (RoM) of the disc-alone model matched well in vitro data. Ligament properties significantly affected only sagittal RoMs (∼3.0-7.1° in flexion and ∼3.8-5.8° in extension at... 

The dummies currently used for predicting vehicle occupant response during frontal crashes or whole-body vibration provide insufficient information about spinal loads. Although they aptly approximate upper-body rotations in different loading scenarios, they overlook spinal loads, which are crucial to injury assessment. This paper aims to develop a modified dummy finite element (FE) model with a detailed viscoelastic lumbar spine. This model has been developed and validated against in-vitro and in-silico data under different loading conditions, and its predicted ranges of motion (RoM) and intradiscal pressure (IDP) maintain close correspondence with the in-vitro data. The dominant frequency... 

Background: Functional knee braces are extensively used for partially and completely torn anterior cruciate ligament (ACL) patients and those who have undergone ACL graft reconstruction, in order to support the healing ACL, improve the joint's functional stability, and restore the normal joint kinematics. Research question: Does wearing braces alter the arthrokinematics of the ACL deficient knees during lung exercise? Methods: For ten male unilateral ACL deficient subjects, 3D knee models were reconstructed from CT images, acquired in rest position. Sagittal plane fluoroscopy was then performed throughout a complete cycle of lunge in braced and non-braced conditions. The 3D kinematics of the... 

Evaluation of spinal range of motions (RoMs) and movement coordination between its segments (thorax, lumbar, and pelvis) has clinical and biomechanical implications. Previous studies have not recorded three-dimensional primary/coupled motions of all spinal segments simultaneously. Moreover, magnitude/direction of the coupled motions of the thorax/pelvis in standing posture and lumbopelvic rhythms in the frontal/transverse planes have not been investigated. This study, hence, used an inertial tracking device to measure T1, T5, T12, total (T1-T12) thoracic, lower (T5-T12) and upper (T1-T5) thoracic, lumbar (T12-S1), and pelvis primary and coupled RoMs as well as their movement coordination in... 

Ligaments assist trunk muscles in balancing external moments and providing spinal stability. In absence of the personalized material properties for ligaments, finite element (FE) models use dispersed data from the literature. This study aims to investigate the relative effects of eight different ligament property datasets on FE model responses. Eight L4-L5 models distinct only in ligament properties were constructed and loaded under moment (15 N m) alone or combined with a compressive follower load (FL). Range of motions (RoM) of the disc-alone model matched well in vitro data. Ligament properties significantly affected only sagittal RoMs (∼3.0–7.1° in flexion and ∼3.8–5.8° in extension at... 

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...