Recent Adopted

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  • Three-Dimensional Finite Element Analysis of Orthodontic Tooth Movement at Different Alveolar Bone Heights
    WANG Jing YANG Tianmei ZHANG Jian MA Fujuan GE Zhenlin
    Adopted date: July 16,2024
    [Abstract](12) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To investigate the effects of different alveolar bone heights and orthodontic forces on tooth displacement and periodontal stress changes, and to guide the optimization of orthodontic treatments. Method Four groups of mandibular dentition finite element models with normal alveolar bone height, resorption 1/3, resorption 1/2, and resorption 2/3 were established. Next, the lingual, distal, and intrusion movements of the mandibular central incisors were simulated with different loads. Finally, the trend of tooth displacement and the change of displacement amount, as well as the distribution and size change of periodontal stress were analyzed. Results With alveolar bone height decreased and orthodontic force increased, the maximum periodontal equivalent force increased and the stress concentration in cervical increased and the displacement of each observation point and the crown-root displacement difference increased, the tendency for tipping movement of the teeth increased in the three movements. Conclusions ①The reduction in alveolar bone height may exacerbate stress concentrations at the top of the alveolar ridge as well as the tendency for tipping movement. ②It is recommended that: for 1/3 of the alveolar bone resorption: lingual movement force of 50~100 g, distal movement force of 100~150 g, and intrusion movement force of 50~75 g; for 1/2 resorption of the alveolar bone: lingual movement of less than 50 g, distal movement of 50~100 g, and intrusion movement of less than 50 g; for 2/3 resorption of the alveolar bone height: lingual and intrusion movements should not be applied; distal movements with a force of less than 50 g are appropriate.
    Influence of subchondral bone vascularisation on bone microstructure in developmental hip dysplasia
    YAN Jiren ZHANG Xiaofu CHU Linyang ZHONG Biao
    Adopted date: July 16,2024
    [Abstract](10) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To study the effects of abnormal mechanical load in developmental dysplasia of the hip (DDH) on the bone microstructure and blood vessels of the subchondral bone, and the correlation between the bone microstructure and blood vessels. Methods A newborn rat DDH model was constructed using the swaddling method, and histological staining such as hematoxylin-eosin staining, safranin-fast green staining, and immunohistochemical staining were performed on the articular cartilage and subchondral bone of the femoral head. The bone microstructure of the subchondral bone was analyzed by micro-computed tomography (Micro-CT). Results DDH rats showed degeneration of articular cartilage, accompanied by deterioration of the bone microstructure of the subchondral bone, decreased bone formation, and increased vascular formation. The level of vascular formation in the subchondral bone was positively correlated with the degree of deterioration of the bone microstructure. Conclusion Abnormal mechanical load in DDH leads to degeneration of articular cartilage, increased vascular formation in the subchondral bone, and deterioration of the bone microstructure of the subchondral bone. The correlation analysis reveals that abnormal vascular formation in the subchondral bone may be an important reason for the deterioration of the bone microstructure and the progression of DDH. This study provides a new research direction to explore the development of DDH.
    Research on fatigue detection of walking with backpack load based on random forest algorithm
    caoyan liuzhuohan wuxie
    Adopted date: July 16,2024
    [Abstract](10) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective: Wearable inertial sensor (IMU) technology and Random forest (RF) algorithm were used to detect the fatigue level of long-distance backpack walking, and the feasibility and optimal IMU combination scheme were explored. Methods: Thirty healthy male college students were recruited to carry out long-distance backpack walking. Xsens MVN Link inertial motion capture system and Borg-RPE fatigue scale were used to collect kinematic data and subjective fatigue values of load-bearing walking, and fatigue was divided into 3 levels: no fatigue, moderate fatigue and severe fatigue. The original data were extracted, gait segmentation, data screening and feature extraction were carried out, and RF model was used for machine learning of sample features. Finally, the accuracy rate, confusion matrix and AUC value were calculated to evaluate the detection effect of different IMU combinations. Results: The accuracy of one right femur IMU was 82.55%, and the accuracy of five IMU combinations was 87.94%. In a combination of IMUs, at least one upper body IMU is included, and the left limb has more IMU than the right. The RF model had a higher level of fatigue detection for load-bearing walking, and the AUC values of level 3 fatigue were 0.99, 0.97 and 0.99, respectively, when four IMUs were used. Conclusions: IMU technology and RF algorithm have high accuracy and classification ability in the third-level fatigue detection task of walking with backpack load. In practical application, it is recommended to use 1-5 IMUs, and the combination of upper body IMU and lower limb IMU configuration scheme.
    Influence of the active force of occupant neck muscles on the kinematic response of the head under load impacts
    He Lijuan Wang Fuyang Li Haiyan Zhang Xinyu Cui Shihai Lv Wenle Ruan Shijie
    Adopted date: July 16,2024
    [Abstract](7) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To provide basic data for the development of automobile crash safety standards that meet Chinese national conditions and have Chinese characteristics, the influence of muscle active force on the kinematic response of the occupant"s head and neck under load impact was investigated. Methods Based on the CT images of 50th percentile male volunteers with Chinese physical characteristics, a finite element model of the neck containing cervical vertebrae, muscles, and fat was constructed, and the validity of frontal and side impact simulation was verified for the model, and a beam unit was added to the model to simulate the active force of neck muscles. Results The simulation experimental data of the developed model and the volunteer experimental data have the same trend and good agreement, which verifies the validity of the model. As shown by the simulation comparison results between the activated state model and the subjected state model, the peak motion of the activated state model is lower than that of the subjected state model, and in the side collision, the y-direction displacement of the head of the activated state model can’t fully match the volunteer experimental channel. Conclusions Muscle active force can maintain the posture and stability of the body, and the activation curves as well as the muscle active force produced by different individuals vary due to the different physiological cross-sectional area of muscles and other factors. The finite element model of male neck developed in this study is based on the latest statistical data of male physique in China, with detailed anatomical structure and high biological fidelity, which can be used for the study of neck injury mechanism of Chinese physique medium-sized men.
    Progress in the biomechanical study of flat foot formation and therapy
    Hu Zongxiang Li Qiang Chen Xuecan Wang Xiangdong
    Adopted date: June 27,2024
    [Abstract](32) [HTML](0) [PDF 0.00 Byte](0)
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    Abstract: To understand the pathogenesis of flatfoot and provide reference for improved treatment options. This paper reviewed the causes and treatment of PubMed, Web of Science, CNKI and Wanfang. The reasons for the formation of flat feet include congenital factors and acquired factors, while the treatment methods mainly include orthopedic insoles, physical therapy, surgical therapy and exercise therapy. These methods are able to correct foot structural abnormalities, optimize biomechanical properties and improve foot stability and range of motion. For future research will use advanced imaging and simulation technology for accurate assessment, new materials and the application of non-surgical therapy will be able to relieve long-term symptoms, and genetic research will promote the development of early diagnosis and personalized treatment, the use of intelligent orthosis will realize real-time monitoring and dynamic adjustment, to provide more flat foot assessment, intervention and treatment of more effective methods and means.
    Characterization of the Symmetry of Gait Parameters in Children with Mild Leg Length Discrepancy
    LU Xiaoying LI Yang LI Yiying YU Yan JIANG Shuyun
    Adopted date: June 27,2024
    [Abstract](22) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To analyze the symmetry characteristics of gait dynamics, kinematics and spatial and temporal parameters in children with mild Leg Length Discrepancy (LLD), and to explore the possible influence or risk of LLD on children"s growth, so as to provide theoretical basis for early assessment and intervention. Methods Using a modified traditional three-dimensional model, 29 markers were placed on the body surface of each subject to collect gait parameters and calculate the symmetry index (SI). The spatial distance of the ipsilateral markers between anterior superior iliac spine and the external ankle in the standing position was recorded as the length of the legs, and children with more than 0.5 cm and less than 2.5 cm leg length difference were included in the group of 59 cases with mild LLD, and those with less than 0.5cm leg length difference were included in the group of 42 cases as the control group, and then divided into the groups of 1-6 and 7-14 years of age according to the ages of the children and were statistically analyzed separately, and the symmetry index difference of the gait parameters was calculated between groups. Results The SI of the vertical ground reaction force and the maximum power of the knee joint were significantly different between children with mild LLD and normal children aged 1-6. The SI of the pelvis motion were significantly different between children with mild LLD and normal children aged 7-14. Conclusions The imbalance in muscle strength and control of the unequal leg length in children in the younger age groups, and the imbalance at the pelvic motion appears as the gait pattern matures, suggests clinical attention or early assessment.
    Advances in AI-enabled total hip arthroplasty
    Huang Yinshu Shan Haojie Yu Xiaowei
    Adopted date: June 19,2024
    [Abstract](24) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Preoperative planning, intraoperative navigation, and postoperative rehabilitation of total hip arthroplasty have been significantly enhanced by the integration of Artificial Intelligence (AI) technology. This review summarizes the latest advancements in AI technology for medical image segmentation and registration, with a particular focus on its application in total hip arthroplasty. The notable differences between medical and natural images present challenges for the design of AI algorithms. Deep learning techniques, especially CNN, U-Net, and Transformer models, have demonstrated outstanding performance in various medical image segmentation and registration tasks. AI technology, through deep learning analysis of CT images, has significantly improved the accuracy of identifying hip pathologies. In terms of intraoperative guidance, AI systems provide real-time navigation and precise positioning for surgeries by utilizing intelligent segmentation and motion state simulation, effectively enhancing surgical efficiency. AI technology also encompasses surgical cost prediction and postoperative recovery, offering robust data support for medical decision-making through methods such as Markov models. As deep learning technology continues to advance, the analysis of medical images is progressively achieving automation and intelligence, which has significant clinical implications for improving patients' overall surgical experiences and outcomes, and suggests potential new breakthroughs in the field of medical imaging in the future.
    The Influence of Age on Body Dynamic Stability during Different Directions Turning
    BO Yulong CHE Chengzhang WU Yunzhi PAN Yuhan ZHANG Cui
    Adopted date: June 19,2024
    [Abstract](32) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Purpose: This study aims to describe the different characteristics of dynamic stability characteristics between older adults and young adults during continuous turning walking in different directions. Methods: Fifteen healthy older adults and fifteen healthy young adults were recruited to finish continuous eight-shaped clockwise and counterclock turning. Three-dimensional motion capture system was used to collect kinematics data based on 43 bone markers. Gait and center of mass velocity parameters were proceeded by V3D software. Margin of stability in the forward and medial at foot contact and lift-off were analyzed. Results: Compared with clockwise turning, step width of the inner leg was increased(Clockwise turn for young adults: 0.15 ± 0.03 body height, counterclockwise turn for young adults: 0.17 ± 0.02 body height, clockwise turn for older adults: 0.16 ± 0.02 body height, counterclockwise turn for older adults: 0.15 ± 0.02 body height), and margin of stability in the forward direction at inner leg toe-off instant was decreased during counterclockwise turning in young adults(Clockwise turn for young adults: -0.78±2.64 cm, counterclockwise turn for young adults: -2.19±2.22 cm, clockwise turn for older adults: -1.15±3.12 cm, counterclockwise turn for older adults: -0.48±3.42 cm), whereas there were no significant differences in older adults. Conclusions: Step width of the inner leg and forward dynamic stability were influenced by age and turning direction simultaneously. More cautious strategies was adopted by healthy older adults to maintain anterior and medial stability during continuous turning walking. It is suggested that older adults should increase turning training in daily life, to improve medial-lateral control ability and confidence of turning.
    Acute Effects of Heel-to-toe Drop of Running Shoes on Patellofemoral Joint and Achilles Tendon Loading in Runners with Patellofemoral Pain
    Gu Yu Zheng Zhiyi Zeng Quanshou Yang Chen Wan Xianglin
    Adopted date: June 19,2024
    [Abstract](21) [HTML](0) [PDF 0.00 Byte](0)
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    Abstract: Objective To determine the acute effects of heel-to-toe drops (5mm, 0mm, -11mm) of running shoes on the loading of the patellofemoral joint and Achilles tendon (AT) in runners with patellofemoral pain (PFP) during running. Methods Sixteen runners with PFP ran in running shoes in different heel-to-toe drops while retroreflective markers and ground reaction force were required by applying infrared motion capture system and a three-dimensional force plate. Patellofemoral joint stress (PFJS), AT force were calculated based on biomechanical models of patellofemoral joint and AT. Results When PFP runners ran in negative heel shoes, the PFJS during 39%-47% of the stance phase(P<0.001), the maximum PFJS during the stance phase and cumulative PFJS(P<0.05) was lower than positive heel shoes, while the AT force during 12%-46% of the stance phase(P<0.001) and cumulative AT force(P=0.001) was greater than positive heel shoes. Additionally, the AT force during 12%-31% of the stance phase(P<0.001) and cumulative AT force in negative heel shoes was greater in zero heel shoes. Conclusions Running in negative heel shoes decreases the PFJS and cumulative PFJS compared with positive heel shoes, potentially reducing the risk of further development of PFP. However, it increases AT force and the cumulative AT force compared with zero and positive heel shoes, which may increase the risk of AT injury.