Sit-stand movement is one of the most common movement behaviors of the human body. The knee joint is the main bearing joint of this movement. Thus, the dynamic analysis of knee joint during this movement has deeply positive influences. According to the principle of moment balance, the dynamics of the knee joint during the movement were analyzed. Furthermore, combined with the data obtained from optical motion capture and six-dimensional ground reaction force test, the curve of knee joint torque was calculated. To verify the accuracy of the analysis of dynamic, the human body model was established, the polynomial equations of angle and angular velocity were fitted according to the experimental data, and the knee joint simulation of the movement was carried out. The result revealed that in terms of range and trend, the theoretical data and simulation data were consistent. The relationship between knee joint torque and ground reaction force was revealed based on the variation law of knee joint torque. During the sit-stand movement, the knee joint torque and the ground reaction force were directly proportional to each other, and the ratio was 5 to 6. In the standing process, the acceleration first increased and then decreased and finally increased in reverse, and the maximum knee torque occurred at an angle of about 140°. In the sitting process, the torque was maximized in the initial stage. The results of the dynamics analysis of knee joint during sit-stand movement are beneficial to the optimal design and force feedback control of seated rehabilitation aids, and can provide theoretical guidance for knee rehabilitation training.
Humans ; Hip Joint ; Biomechanical Phenomena ; Movement ; Knee Joint ; Torque

The series of YY/T 0987 standards converted from the corresponding ASTM (American Society for Testing and Materials) standards regulate the marking medical devices and testing methods for passive implants in the magnetic resonance environment. Along with the advancement of scientific cognition and the development of technology, the ASTM continuously amends and updates standards. This article studies the new version of ASTM standards and analyzes the advancing parts newly added as compared to the current YY/T 0987-2016 standard and eventually pinpoints some problems that remained to be solved. Except for the standard for image artifacts, this study found out that other standards had also been constantly updated, such as the standard of ASTM F2503 for marking medical devices extends its referenced documents and adds some ISO standards in, meanwhile, the test method on magnetically induced displacement force, radio frequency induced heating and magnetically induced torque also had been significantly adjusted and improved accordingly. This article recommends that domestic standards need to keep pace with the latest edition of ASTM F standards and to supplement new research achievements timely, just in order to provide a better normalization, guidance and support to the development of Chinese passive implants industry.
Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Prostheses and Implants ; Radio Waves ; Torque ; United States

OBJECTIVE: Develop an intelligent equipment that can perform multiple modes of functional exercise on the knee joint, and can accurately measure and control strength, angle, angular velocity, time, frequency and so on. METHODS: Using geared motors, magnetic powder brakes and synchronous belt wheel sets and other mechanical structure and transmission technology combined with sophisticated mechanical design methods, the knee joint multiple functional exercise methods are cleverly integrated; a highly reliable PLC is used as the control core; the resistance torque out-put by the equipment is accurately controlled by adjusting the size of the exciting current; the angle sensor is used to accurately measure the rotation angle around the axis; and the error of each parameter index and the actual measured value is controlled within 5%. RESULTS: The developed prototype has a compact structure and a simple and convenient method of use. Based on the control of joint parameters such as resistance, the expected goal is achieved. CONCLUSIONS The equipment can carry out diversified, accurate and automatic rehabilitation treatment for knee joint diseases, and has certain social and economic benefits.
Biomechanical Phenomena ; Knee Joint ; Powders ; Rotation ; Torque

Based on the biomechanical mechanism of human upper limb, the disadvantages of traditional rehabilitation training and the current status of upper limb rehabilitation robot, a six degree of freedom, flexible adjustment, wearable upper limb rehabilitation exoskeleton design scheme is proposed. Firstly, the mechanics of each joint of the upper limb is analyzed, and the virtual prototype design of the whole mechanical structure of the upper limb rehabilitation wearable exoskeleton is carried out by using CATIA three-dimensional software. The tooth transmission of the forearm and the upper arm single row four point contact ball bearing with internal/external rotation and the shoulder flexible passive adjustment mechanism (viscoelastic damper) are innovatively designed. Then, the joints of the upper limb rehabilitation exoskeleton are analyzed, theoretical analysis and calculation of the driving torque, the selection of the motor and gearbox of each driving joint are carried out. Finally, the whole finite element analysis of the upper limb exoskeleton is carried out. The research and experimental results showed that the design scheme of the upper limb exoskeleton assist structure is highly feasible, which can help the patients with upper limb paralysis and motor dysfunction self-rehabilitation.
Biomechanical Phenomena ; Exoskeleton Device ; Humans ; Robotics ; Stroke Rehabilitation ; Torque ; Upper Extremity ; Wearable Electronic Devices

This study designed an isokinetic muscle strength rehabilitation training equipment, based on oil resistance. The equipment detected joint angles during movement through displacement sensors to measure the angular velocity in real-time. Then it can achieve flow resistance adjustment and constant velocity movement, based on the flow area of the proportional valve calculated by PID algorithm and the deviation between the set speed and the measured speed. The equipment can also collect muscle strength during exercise through force-sensitive sensors to achieve real-time and accurate assessment of muscle strength. Moreover, the study preliminarily certificated the isokinetic motion the results showed that the mean error of peak torque test is less than 5%, and the correlation is between 0.89 and 0.92 (
Exercise Therapy ; Humans ; Movement ; Muscle Strength ; Muscle, Skeletal ; Torque

BACKGROUND: In the osseointegration of dental implants, the implant surface properties have been reported to be some of the most important critical factors. The effect of implant's surfaces created by resorbable blast media (RBM) followed by laser ablation on bone tissue reactions was examined using the removal torque test and histomorphometric analysis.METHODS: Two types of dental implants, RBM-laser implants (experimental group) and RBM implants (control group) (CSM implant system, Daegu, Korea; L=6 mm, diameter=3.75 mm) were placed into the right and left distal femoral metaphysis of 17 adult rabbits. Six weeks after placement, removal torque was measured and histomorphometric analysis was performed.RESULTS: The mean removal torque was 24.0±10.2 Ncm and 46.6±16.4 Ncm for the control and test specimens, respectively. The experimental RBM-laser implants had significantly higher removal torque values than the control RBM implants (p=0.013). The mean values of total and cortical bone to implant contact (BIC) were respectively 46.3±10.8% and 65.3±12.5% for the experimental group, and 41.9±18.5% and 57.6±10.6% for the control group. The experimental RBM-laser implants showed a higher degree of total and cortical BIC compared with RBM implants, but there was no statistical significance (p=0.482, 0.225).CONCLUSION: The removal torque and BIC of the test group were higher than those of the control group. In this study, the surface treatment created by RBM treatment followed by laser ablation appears to have a potential in improving bone tissue reactions of dental implants.
Adult ; Bone and Bones ; Daegu ; Dental Implants ; Humans ; Korea ; Laser Therapy ; Osseointegration ; Rabbits ; Surface Properties ; Torque

OBJECTIVE: To investigate functional outcomes after the application of a critical pathway for inpatient rehabilitation of total knee arthroplasty (TKA).METHODS: A total of 184 patients (57 males and 127 females; average age, 71.5±5.9 years) who underwent unilateral or bilateral TKA were included. The critical pathway included early, intensive individualized rehabilitation exercises. Patients completed the following performance-based physical function tests: the stair climbing test (SCT), 6-minute walk test (6MWT), and Timed Up and Go test (TUG) as well as measurement of isometric knee flexor and extensor strength of the operated knee, gait speed, and range of knee flexion and extension. Self-reported physical function and pain were measured using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS), respectively, and self-reported quality of life was measured using the EuroQoL 5 dimension (EQ-5D) questionnaire. These evaluations were performed preoperatively and at 1 month and 3 months postoperatively.RESULTS: Performance-based and self-reported physical function and quality of life measures improved nonlinearly over time. Specifically, the 6WMT, TUG, gait speed, WOMAC-pain, WOMAC-function, VAS, and EQ-5D scores showed a significant improvement at 1-month post-TKA, whereas SCT, peak torque of the knee extensors and flexors, and WOMAC-stiffness scores showed gradual, but substantial, improvements over 3 months. There were between-group differences (unilateral and bilateral TKA groups) in the time course of the SCT, 6MWT, TUG, VAS, WOAMC-stiffness, and WOMAC-function results.CONCLUSION: Patients who underwent critical pathway rehabilitation after TKA showed significant improvements in functional measurements during the first 3 months post-surgery.
Arthroplasty ; Arthroplasty, Replacement, Knee ; Critical Pathways ; Exercise ; Female ; Gait ; Humans ; Inpatients ; Knee ; Male ; Ontario ; Osteoarthritis ; Quality of Life ; Rehabilitation ; Torque ; Visual Analog Scale

Muscle strength training plays an important role in improving limb movement function, preventing muscle atrophy and promoting muscle function recovery in patients with various bone and joint diseases. The sports function of elbow joint is closely related to people's daily life activity ability. At present, Chinese muscle strength training devices are depended on import. Therefore, it is of great significance to develop muscle strength training devices. Based on the concepts and characteristics of isometric training, isotonic training, passive training and isokinetic training, in the upper computer, the servo driver and servo motor are controlled through the LabView interface, and the real-time torque is detected by the torque sensor, realizing four training modes. The main parameters of the multi-mode elbow joint muscle strength training device meet the requirements, and the trainers have a good experience.
Elbow Joint ; physiology ; Humans ; Muscle Strength ; Muscle, Skeletal ; Resistance Training ; Torque

PURPOSE: Chemically strong-acids (HF and HCl/H₂SO₄) dual etching implant surfaces have higher strengths of osseointegration than machined implant surfaces. However, the dual acid treatment deteriorates the physical properties of the titanium by weakening the fatigue resistance of the implant and causing microcracks. The removal torque comparison between the dual-acid etched (hydrochloric acid, sulfuric acid, HS) and single-acid etched implants (hydrochloric acid, H) could reveal the efficiency of implant surface acid treatment. MATERIALS AND METHODS: Nine 3.75 × 4 mm dual-acid etched SLA implants and nine single-acid etched SLA implants were inserted into New Zealand rabbit tibias. After 10 days, removal torque, roughness, and wetting angle were measured. RESULTS: Mean removal torque values were as follows: Mean removal torque were 9.94 Ncm for HS group and 9.96 Ncm for H group (P=.995). Mean surface roughness value were 0.93 µm for HS group and 0.84 µm for H group (P=.170). Root mean square roughness (RSq) values were 1.21 µm for HS group and 1.08 µm for H group (P=.294), and mean wetting angle values were 99° for HS group and 98° for H group (P=.829). Statistical analysis showed no significant difference between the removal torques, roughness, or wetting angles of the two groups. CONCLUSION: In this experiment, we found no significant difference in removal torque, roughness, or wetting angle between dual-acid etched and single-acid etched implants.
Fatigue ; Osseointegration ; Rabbits ; Sulfur ; Tibia ; Titanium ; Torque

PURPOSE: The aim of this study was to confirm if Laser-treated implants were soaked in 0.9% NaCl solution for 2 weeks could increase the surface hydrophilicity, and the Remoal Torque of each implant that inserted in rabbit tibia for initial healing period of 10 days. MATERIALS AND METHODS: Twenty machined titanium surface screws were produced with a diameter 3 mm, length 8 mm. Ten screws had their surface treated with a laser only (laser treated group), and the other 10 were soaked in saline for 2 weeks after surface treatment with a laser (laser treated + saline soaked group). Implants were inserted in rabbit tibia (ten adult New Zealand white rabbits), and the RTQ of each implant was measured after 10 days. The wettability among implants was compared by measuring the contact angle. Surface composition and surface topography were analyzed. RESULTS: After 10 days, the laser treat + soaking group implants had a significantly higher mean RTQ than the laser treated implants (P = .002, < .05). There were no significant morphological differences between groups, and no remarkable differences were found between the two groups in the SEM analysis. CONCLUSION: Saline soaking implants is expected to produce excellent RTQ and surface analysis results.
Adult ; Humans ; Hydrophobic and Hydrophilic Interactions ; New Zealand ; Tibia ; Titanium ; Torque ; Wettability