فهرست مطالب ایمان وحدت

The aim of this study was to investigate the structure of passive resistive moment of elbow joint acting against movement and also to apply it in order to create a similar moment mechanism for rehabilitation and practical equipment to perform joint movements according to sports medicine and rehabilitation scopes and notifications. Eight healthy men were recruited in order to establish the subjects group which had no history of neurological or musculo-skeletal pathology. Five cyclic passive elbow flexions were performed by a Cybex isokinetic dynamometer at 15 and 45 deg/s through 0 to 130 degree of range of motion. The experimental data was exported to the MATLAB software for analysis. Investigation of the structure of the components of the passive resistive moment showed that the most compatibility with passive resistive moment observed in the combined use of weight and pneumatic resistive moments. Finally it was concluded that the possibility of reaching optimized movement, reduction of damage to the tissues and joints and also reduction of energy dissipation due to inertia were provided by the use of the function of natural resistive moment of the limbs in order to create a resistive mechanism for rehabilitation and practical equipment.

The goal of the present study was to evaluate spasticity variations by increase the velocity of motion and MAS value in the elbow flexor and extensor muscles at extension and flexion of CVA patients elbow joint according to the biomechanical indices. Fifteen adult patients with a history of stroke and upper-extremity spasticity volunteered to participate in this study and fifteen healthy subjects were recruited in order to establish the control group. The degree of spasticity was evaluated for each patient using the MAS. CPM tests were imposed in elbow extension and flexion and the biomechanical indices were calculated at each of the following velocities: 15، 45، 75 and 120 º/s. It seemed a regular increment of the viscoelastic and viscose stiffness indices by increasing the velocity of motion and the rate of MAS value in both extension and flexion in all test groups and also there was significant regular increment of elastic stiffness index by increasing the velocity in both extension and flexion between the control group and group 1 and also irregular increment between group1 and group 2 and 3 and also the effect of mentioned index was decreased at higher level of MAS. it seemed the more effect of elastic stiffness in spasticity in CVA patients at lower level of MAS and more effect of viscose stiffness in higher level of MAS and also results showed the increment of viscose stiffness by increment of speed of motion and the rate of MAS.

Many researches have been conducted inorder to explore the ingredients of joint impairements like muscle spasticity and joint rigidity in which mechanical viscoelastic properties have been quantified during the joint movement. The aim of this study was to explore passive viscose and elastic properties at flexion and extension of the human elbow joint and to determine a mathematical torque-angle relation for the measured torque. The method of this study was descriptive-analysis. Passive resistant torque was measured for 5 healthy subjects by Continues Passive Motion (CPM) at four different velocities for full range of extension and flexion by an isokinetic dynamometer. To extract viscose and elastic properties of the passive resistant torques of flexion and extension of the elbow، measures were extracted using MATLAB-R2009 software and statistical analyses were done by SPSS version 16. The results showed 3 total slopes of the passive torque curves by increasing the velocity of movement and also greater slope at the beginning and the end range of passive torque curves appeared in both extension and flexion. I It seemed to be a nonlinear relation and depending on elastic and viscose properties on angular movement and velocity at the passive torques. Viscose and elastic properties were dependent on velocity and movement of muscle-tendon unit. Finally it was concluded from this study the possibility of evaluation and analysis the mechanical function of spanning tissues using a simple torque-angle relation for the passive torques with assumption of linear dependency on elastic and viscose properties and independency of viscose properties on angular movement.

The goal of the present study was to improve the extension and flexion of the elbow joint for rehabilitation purposes، in terms of energy dissipation and of injuries caused by stress imposed on connective tissue by exercise equipments during force transfer، by investigation of viscoelastic property variations during change in speed of motion. A sample of five men without any previous neuromuscular impairment of the elbow joint was chosen by the BMI factor. The passive continuous motion test (CPM) was performed by the CYBEX isokinetic system in the extension and flexion movements of the elbow joint of the left hand، at 4 different speeds (15، 45، 75 and120 Deg/s) during 5 consecutive cycles at the range of motion of about 0 to 130 degrees. The experimental data was exported to the MATLAB software for analysis. In order to determine viscoelastic property effects and biomechanical parameters، we used a passive viscoelastic mechanical model constructed by 3 elements for simulation، and also we used the curve fitting method to derive the elastic and viscose coefficients for the model.، . Results of experiments showed that by increasing the speed of motion، the value of work done، hysteresis and elastic coefficient increased and the value of viscose coefficient decreased. Also، it appeared that by increasing the speed of motion، the effect of viscose resistance on the passive torque curves increased. In addition، there was significant correlation between the action of the mechanical model and the action of the concerned limbs، during the movement. It was concluded that in order to improve motion and to reduce imposed risks and injuries to joints and limbs، rehabilitation exercises better be performed at lower speeds and with rehabilitation equipments supported by viscoelastic resistant force.