Shanghai GaiTech Scientific Instruments Co.

Shanghai, China

Shanghai GaiTech Scientific Instruments Co.

Shanghai, China
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Yang T.-F.,Henan University of Science and Technology | Wang J.-W.,Shanghai Ninth Peoples Hospital | Hu Z.-G.,Henan University of Science and Technology | Zhao W.-M.,Henan University of Science and Technology | And 3 more authors.
Yiyong Shengwu Lixue/Journal of Medical Biomechanics | Year: 2017

Objective: To establish a three-dimensional(3D) finite element model of cervical vertebrae (C1-7), and study its biomechanical properties under muscle force by cervical traction, so as to provide references for clinical treatment. Methods: On the basis of nonlinear finite element model of normal cervical vertebrae and combined with clinical traction methods, cervical traction at the extension angle of 0°, 10°, 20°, 30°, 40° under the same traction weight, was simulated by finite element analysis (FEA) software to obtain and select the joint force and muscle force that were appropriate for FEA on the model. Results: In the process of cervical extension by traction, under the muscle force, the average maximum equivalent stress of cervical vertebrae, intervertebral disc and uncovertebral joints increased by 4.86, 1.79, 0.69 MPa, respectively, and the average maximum relative displacement of cervical vertebrae in sagittal and vertical axis direction increased by 11.1, 1.26 mm, respectively. The biomechanical properties of cervical traction were similar to the FEA results reported in the literature. Conclusions: Neck muscles play an active role in promoting the stress and displacement of cervical vertebrae, intervertebral discs and uncovertebral joints and it should be taken into consideration when performing cervical traction in clinic. In addition, the traction angle should not be too large: 0°-20° is generally recommended as a relatively safe angle range at the initial stage. Copyright © 2017 by the Editorial Board of Journal of Medical Biomechanics.


Liu H.,Shanghai University of Traditional Chinese Medicine | Zhang X.-L.,Shanghai University of Traditional Chinese Medicine | Zhou N.,Shanghai University of Traditional Chinese Medicine | Huang W.-J.,Shanghai Gaitech Scientific Instruments Co. | And 3 more authors.
Yiyong Shengwu Lixue/Journal of Medical Biomechanics | Year: 2017

Objective: To explore the biomechanical mechanisms of correlation between lumbar disc degeneration and sacroiliac joint disorder though investigating the biomechanical characteristics of lumbar disc degeneration with sacroiliac joint disorders. Methods: One normal healthy volunteer and two patients with lumbar disc herniation and sacroiliac joint disorders (one was with sacrum disorders and the other was with ilium disorders) were selected. Their CT data were collected to establish three corresponding lumbar-pelvis finite-element models, and their gait data were also simultaneously collected to drive the AnyBody musculoskeletal model. The muscle force around the lumbar and pelvis as well as the hip joint force were acquired as loading condition for finite element analysis. The stress changes in L4 and L5 intervertebral discs and sacroiliac joints of the patients and normal volunteer were compared. Results: There was no significant difference in the stress of the two sides of L4, L5 disc and two sacroiliac joints in normal model, with a bimodal stress curve. However, in the models of sacrum disorders and ilium disorders, the bimodal stress curve peaks changed, even disappeared. The peak stress differences in left and right side of L4 disc were 0.55 MPa and 0.80 MPa, respectively, the peak stress differences in left and right side of L5 disc were 4.05 MPa and 2.08 MPa, respectively, and the peak stress differences in left and right side of sacroiliac joints were 0.96 MPa and 3.32 MPa, respectively. Conclusions: The lumbar disc degeneration with sacroiliac joint disorder leads to the tilt of the body loading line, and sacroiliac joint disorder can aggravate the imbalances of stress on the body sides. The impact of sacroiliac joint dysfunction cannot be ignored in the treatment of lumbar disc herniation. Copyright © 2017 by the Editorial Board of Journal of Medical Biomechanics.


Yang L.,Hong Kong Polytechnic University | Yang L.,Shanghai Gaitech Scientific Instruments Co. | Gong H.,Hong Kong Polytechnic University | Gong H.,Beihang University | Zhang M.,Hong Kong Polytechnic University
Journal of Mechanics in Medicine and Biology | Year: 2012

This study focuses on the transmissibility of whole body vibration stimuli through human body in different standing postures to explore the mechanism in which vibration stimuli could be better used as a regimen for bone loss. Five volunteers were guided to stay at three standing postures and imposed of frequency-adjustable vibration stimuli on the plantar surfaces side-alternately. Motion capture system was used to acquire the vibration signals at head, pelvis, knee up, knee down and ankle, from which the transmissibility of vibration stimuli can be obtained. The results showed that transmissibility of vibration stimuli was closely correlated with frequency and skeletal sites. Transmissibility of vibration stimuli in head was much smaller than any other skeletal sites. Transmissibility in the ankle was always in the vicinity of unit one in all the three postures for the vibration stimuli applied side-alternately on the plantar surfaces of both feet. There was an obvious peak around 9 to 11 Hz in the transmissibility curves for knee joint and pelvis. In the resonant peak, transmissibility of vibration stimuli in knee joint and pelvis both exceeded unit one and reached 150%. As the frequency increased after 11 Hz, transmissibility of vibration stimuli decayed rapidly as a function of frequency and dropped to 25% at 30 Hz. This study may help to gain insight into the interaction mechanism between mechanical vibration stimuli and the responses of human musculoskeletal system. © 2012 World Scientific Publishing Company.


Hu X.-H.,Henan International Central Hospital | Hu X.-H.,Chinese PLA 113 Hospital | Hong X.,Institute of Forensic Science | He B.-F.,Institute of Forensic Science | And 3 more authors.
Yiyong Shengwu Lixue/Journal of Medical Biomechanics | Year: 2014

Objective: To build a 3D finite element model of the whole cervical spine by using Simpleware software, as well as validate and analyze the model, so as to provide a reliable model for exploring the mechanism of cervical spine injury. Methods: The 3D entity model of the whole cervical spine C1-7 was established based on CT tomography images, medical image processing software Simpleware, reverse engineering software Geomagic, which was imported to Hypermesh for meshing, adding ligaments and introducing facet joint contact relation, etc., thus to establish the finite element model of the whole cervical spine C1-7. Biomechanical properties of the cervical spine under flexion, extension, lateral bending and torsion were simulated by ANSYS. Results: The established model was proved to be accurate and reliable, and its range of motion (ROM) under flexion, extension, lateral bending and axial rotation was similar to in vitro experiment and finite element analysis results in related literatures. The stress of intervertebral disc was concentrated on the compression side of the vertebral body, and the cervical spine C4/5 was more prone to have a stress concentration. Conclusions: The finite element model of the whole cervical spine C1-7 can effectively simulate the biomechanical characteristics of the cervical vertebra, which establishes a good foundation for the follow-up studies on whiplash injury of the cervical spine. Copyright © 2014 by the Editorial Board of Journal of Medical Biomechanics.


Liu S.-Z.,Chongqing University | Hu Z.-G.,Henan University of Science and Technology | Zhang J.,Shanghai Gaitech Scientific Instruments Co.
Yiyong Shengwu Lixue/Journal of Medical Biomechanics | Year: 2015

Objective: To analyze the badminton athletes'dynamic responses in their lower limbs under impact loads. Methods: A human musculoskeletal model was established based on AnyBody Modeling System software and verified by measuring surface electromyography (EMG). The muscle force, joint force, joint torque of lower limbs during right Front-Court Lunge Step in badminton were studied by inverse dynamic simulation and analysis through Vicon motion capture system and force platform. Results: The musculoskeletal model was validated to be effective by EMG. During right Front-Court Lunge Step in badminton, the force peak of the hip and ankle joint in Z direction was larger than that in X and Y direction, and the force peak of the knee joint in X direction was larger than that in Y and Z direction. During buffer period, the hip joint in X, Y, Z direction showed adduction, extension and internal rotation torque, respectively, the knee joint in X, Y, Z direction showed abduction, flexion and external rotation torque, respectively, and the ankle joint in X, Y direction showed varus and plantar flexion torque, respectively. The peak torque of the hip, knee and ankle joint in X direction was significantly larger than that in Y and Z direction. Vastus lateralis, biceps femoris, anterior tibial and medial gastrocnemius played a larger role against the ground reaction, while rectus femoris, semitendinosus, soleus played a relatively smaller role against the ground reaction. Conclusions: The established musculoskeletal model in the study can provide a technical platform to analyze athletes' biomechanical properties of lower limbs under impact loads. To avoid sport injuries, more attention should be paid to the effect from ground reaction force load at touchdown instant on hip, knee and ankle joints in anteroposterior and mediolateral direction during footwork similar to Front-Court Lunge Step in badminton, and at the same time, the strength training of vastus lateralis, biceps femoris, anterior tibial and medial gastrocnemius of badminton players should not be ignored during specialized training. Copyright © 2015 by the Editorial Board of Journal of Medical Biomechanics.


Yin C.-S.,Anhui University of Science and Technology | Sun F.,Shanghai Gaitech Scientific Instruments Co. | He Y.,Anhui University of Science and Technology | Shao H.-W.,Anhui University of Science and Technology
Chinese Journal of Tissue Engineering Research | Year: 2013

BACKGROUND: Anybody human modeling and simulation system is a computer-aided ergonomics and biomechanical analysis software, and it is the only software that can analyze the musculoskeletal system completely which can be used to calculate the force deformation of bone, muscle and joint. OBJECTIVE: To investigate the index finger dexterity after cold water stimulation using computing model. METHODS: Based on the available data of the experiment about the index finger movement, the kinematic parameters of index finger in the movement were achieved. Subsequently, a clench fist kinematic model of hand was established with Anybody platform, and then a musculoskeletal model consisting of the extrinsic flexor muscles (flexor digitorum profundus and flexor digitorum superficialis) was developed to describe the changes of muscle force and contraction power in clench fist movement before and after cold simulation through inverse dynamics analysis. RESULTS AND CONCLUSION: After the cold water stimulation, the average angular velocities of the three joints of index finger were decreased during the flexing movement compared to those before cold water stimulation, and the muscle force of flexor digitorum superficialis was increased significantly in the flexing process. The contract power of flexor digitorum profundus decreased obviously, whereas the contract power of flexor digitorum superficialis was decreased slightly. The results indicate that the finger movement takes more time and the muscle force of flexor digitorum superficialis is more sensitive to the cold stimulation, which further indicates the importance of flexor digitorum superficialis in clench fist movement.

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