BACKGROUND: China is seeing a growing demand for rehabilitation treatments for post-stroke upper limb spastic paresis (PSSP-UL). Although acupuncture is known to be effective for PSSP-UL, there is room to enhance its efficacy. OBJECTIVE: This study explored a semi-personalized acupuncture approach for PSSP-UL that used three-dimensional kinematic analysis (3DKA) results to select additional acupoints, and investigated the feasibility, efficacy and safety of this approach. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This single-blind, single-center, randomized, controlled trial involved 74 participants who experienced a first-ever ischemic or hemorrhagic stroke with spastic upper limb paresis. The participants were then randomly assigned to the intervention group or the control group in a 1:1 ratio. Both groups received conventional treatments and acupuncture treatment 5 days a week for 4 weeks. The main acupoints in both groups were the same, while participants in the intervention group received additional acupoints selected on the basis of 3DKA results. Follow-up assessments were conducted for 8 weeks after the treatment. MAIN OUTCOME MEASURES: The primary outcome was the Fugl-Meyer Assessment for Upper Extremity (FMA-UE) response rate (≥ 6-point change) at week 4. Secondary outcomes included changes in motor function (FMA-UE), Brunnstrom recovery stage (BRS), manual muscle test (MMT), spasticity (Modified Ashworth Scale, MAS), and activities of daily life (Modified Barthel Index, MBI) at week 4 and week 12. RESULTS: Sixty-four participants completed the trial and underwent analyses. Compared with control group, the intervention group exhibited a significantly higher FMA-UE response rate at week 4 (χ² = 5.479, P = 0.019) and greater improvements in FMA-UE at both week 4 and week 12 (both P < 0.001). The intervention group also showed bigger improvements from baseline in the MMT grades for shoulder adduction and elbow flexion at weeks 4 and 12 as well as thumb adduction at week 4 (P = 0.007, P = 0.049, P = 0.019, P = 0.008, P = 0.029, respectively). The intervention group showed a better change in the MBI at both week 4 and week 12 (P = 0.004 and P = 0.010, respectively). Although the intervention group had a higher BRS for the hand at week 12 (P = 0.041), no intergroup differences were observed at week 4 (all P > 0.05). The two groups showed no differences in MAS grades as well as in BRS for the arm at weeks 4 and 12 (all P > 0.05). CONCLUSION: Semi-personalized acupuncture prescription based on 3DKA results significantly improved motor function, muscle strength, and activities of daily living in patients with PSSP-UL. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR2200056216. Please cite this article as: Huang XY, Liao OP, Jiang SY, Tao JM, Li Y, Lu XY, Li YY, Wang C, Li J, Ma XP. Three-dimensional kinematic analysis can improve the efficacy of acupoint selection for post-stroke patients with upper limb spastic paresis: A randomized controlled trial. J Integr Med. 2025; 23(1): 15-24.
Humans ; Male ; Female ; Middle Aged ; Acupuncture Points ; Upper Extremity/physiopathology* ; Biomechanical Phenomena ; Single-Blind Method ; Aged ; Stroke/therapy* ; Acupuncture Therapy/methods* ; Stroke Rehabilitation/methods* ; Adult ; Muscle Spasticity/therapy* ; Paresis/physiopathology* ; Treatment Outcome

PURPOSE: The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair. METHODS: Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference. RESULTS: AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively). CONCLUSION In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.
Animals ; Rats, Sprague-Dawley ; Rotator Cuff Injuries/surgery* ; Amnion/transplantation* ; Rats ; Wound Healing ; Rotator Cuff/surgery* ; Male ; X-Ray Microtomography ; Tendons/surgery* ; Biomechanical Phenomena

PURPOSE: To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices (ATD) injury indices, the mapping relationship of lumbar injury between ATD and human body model (HBM) was explored. METHODS: Through the ATD model and HBM simulation, the mapping relationship of lumbar injury between the 2 subjects was explored. The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring. Three seatback recline states of 25°, 45°, and 65° were designed, and the seat pan angle was maintained at 15°. A 23 g, 47 km/h pulse was used. The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results. ATD model was the test device for human occupant restraint for autonomous vehicles (THOR-AV) dummy model and HBM was the total human model for safety (THUMS) v6.1. The posture of the 2 models was adjusted to adapt to the 3 seat states. The lumbar response of THOR-AV and the mechanical and biomechanical data on L1 - L5 vertebrae of THUMS were output, and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed. RESULTS: Both THOR-AV and THUMS were submarined in the 65° seatback angle case. With the change of seatback angle, the lumbar spine axial compression force (F_z) of THOR-AV and THUMS changed in the similar trend. The maximum F_z ratio of THOR-AV to THUMS at 25° and 45° seatback angle cases were 1.6 and 1.7. The flexion moment (M_y) and the time when the maximum M_y occurred in the 2 subjects were very different. In particular, the form of moment experienced by the L1 - L5 vertebrae of THUMS also changed. The changing trend of M_y measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS. CONCLUSION The F_z of ATD and HBM presents a certain proportional relationship, and there is a mapping relationship between the 2 subjects on F_z. The mapping function can be further clarified by applying more pulses and adopting more seatback angles. It is difficult to map M_y directly because they are very different in ATD and HBM. The M_y of ATD and stress of HBM lumbar showed a similar change trend over time, and there may be a hidden mapping relationship.
Humans ; Lumbar Vertebrae/injuries* ; Finite Element Analysis ; Biomechanical Phenomena ; Manikins ; Spinal Injuries/physiopathology*

OBJECTIVES: This study aims to analyze the biomechanics of three kinds of rigid internal fixation methods for condylar head fractures. METHODS: A three dimensional finite element model of the normal mandible was constructed. It was then used to prepare condylar head fracture finite element model and three kinds of rigid internal fixation finite element model (unilateral tension screw, bilateral tension screw, tension screw+titanium plate). The mechanical characteristics and changes of the mandible condyle under the same mechanical conditions were compared among the three different rigid internal fixation methods. RESULTS: The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of unilateral tension screw were 71.03 MPa and 4.72 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 78.45 MPa and 4.50 mm, respectively. The maximum stress of fracture suture was 3.27 MPa. The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of bilateral tension screw were 70.52 MPa and 4.00 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 72.49 MPa and 3.85 mm, respectively. The maximum stress of fracture suture was 2.33 MPa. The maximum equivalent stress and maximum displacement of the non-free end of condyle under the rigid internal fixation method of tension screw+titanium plate were 67.26 MPa and 2.66 mm, respectively. The maximum equivalent stress and maximum displacement of the free end of condyle were 69.66 MPa and 2.50 mm, respectively. The maximum stress of fracture suture was 2.18 MPa. CONCLUSIONS The tension screw+titanium plate rigid internal fixation method is the most conducive to biomechanical distribution for condylar head fractures.
Fracture Fixation, Internal/instrumentation* ; Mandibular Condyle/surgery* ; Biomechanical Phenomena ; Bone Screws ; Finite Element Analysis ; Humans ; Mandibular Fractures/surgery* ; Bone Plates ; Titanium ; Stress, Mechanical

OBJECTIVES: This study explores the differences in fluid flow within alveolar cancellous bone at various sites under orthodontic forces and elucidates the relationship between fluid shear stress and bone remodeling. These fin-dings lay the groundwork for understanding the biomechanical mechanisms of orthodontic tooth movement. METHODS: Stress relaxation tests were performed on human alveolar bone samples to determine material parameters by using the Prony series. An inverse model of alveolar bone was then developed for numerical simulations of fluid-structure interactions to calculate fluid flow within cancellous bone. Meanwhile, a rat model of tooth movement was established to investigate variations in bone remodeling speeds across different regions. RESULTS: The microstructural distribution of cancellous alveolar bone was similar in humans and rats. The bone volume fraction and trabecular thickness gradually decreased from root cervical region to root apical region, while the trabecular space gradually increased. Under the influence of orthodontic forces, fluid shear stress within cancellous bone showed spatial variability across different levels, with the highest shear stress occurring at the root apical region, ranging from 0 to 0.936 6 Pa. Additionally, the rat model of tooth movement indicated that bone remodeling occurred more rapidly at the root apical region. CONCLUSIONS Fluid stimulation has a remarkable effect on al-veolar bone remodeling, causing changes in the structure of alveolar bone and ultimately regulating the speed of structu-ral remodeling.
Bone Remodeling ; Animals ; Tooth Movement Techniques ; Rats ; Alveolar Process/physiology* ; Stress, Mechanical ; Humans ; Biomechanical Phenomena ; Cancellous Bone/physiology* ; Shear Strength

OBJECTIVES: This retrospective study aimed to investigate factors influencing positional changes of the condyle and temporomandibular joint (TMJ) following mandibular defect reconstruction with bone flaps, and to evaluate the biomechanical impacts of flap reconstruction on condylar positioning, thereby providing evidence for optimizing surgical protocols and TMJ functional rehabilitation. METHODS: A retrospective study was conducted on 90 patients undergoing mandibular segmental resection with immediate bone flap reconstruction at Guizhou Medical University Affiliated Stomatological Hospital (June 2019 to May 2024). After strict screening, 50 cases with complete data were analyzed. Clinical parameters (defect size, location, reconstruction method) and craniofacial CT scans at four timepoints [preoperative (T0), 7-10 days (T1), 3 months (T2), and 6 months (T3) postoperatively] were collected. Mimics 20 software facilitated 3D reconstruction for measuring TMJ anterior/posterior/superior joint spaces (Kamelchuk method) and calculating condylar position via the Pullinger index [Ln (posterior/anterior space)]. Vitral and Krisjane methods quantified mandibular linear parameters (ramus length, condylar pole distances to the sagittal plane, angulation) and glenoid fossa morphology. Statistical analyses were performed using SPSS 21.0. RESULTS: Mandibular defect size and location were significant factors influencing postoperative condylar position changes (P<0.05). Compared to preoperative measurements, postoperative condylar anterior, posterior, and superior joint spaces were significantly increased (P<0.001). The most pronounced anterior condylar displacement occurred within 7-10 days postoperatively (P<0.05). In patients with condyle resection, postoperative joint space and angle changes were significant; in patients with condyle preservation, only superior and anterior joint space changes were statistically significant (P<0.05). Additionally, from T1 to T2, the changes in condylar medial-lateral distance, superior joint space, and anterior joint space were negatively correlated with the preoperative condylar position. Compared with preoperative,in the T0-T1 period, condylar medial-lateral distance, posterior joint space, and articular tubercle angle changes were significantly negatively correlated with time (P<0.05). Notably, the angle between the condylar long axis and the coronal axis showed a sustained negative trend from T1 to T3 (P<0.05). CONCLUSIONS Condylar position changes after mandibular defect repair with bone flap reconstruction are associated with the size and location of the defect. Additionally, adaptive remodeling of the temporomandibular joint (TMJ) joint space occurs postoperatively. The phenomenon of anterior displacement of the condyle in the early postoperative period (7-10 days) shows a trend of reduction with prolonged follow-up time, and further sample size research is needed.
Humans ; Retrospective Studies ; Temporomandibular Joint/surgery* ; Mandibular Condyle/surgery* ; Male ; Female ; Adult ; Middle Aged ; Mandibular Reconstruction/methods* ; Mandible/surgery* ; Surgical Flaps ; Tomography, X-Ray Computed ; Young Adult ; Biomechanical Phenomena ; Aged ; Adolescent ; Imaging, Three-Dimensional

Long-term dental implant stability is governed by the synergistic regulation of multiple factors, with occlusal parameters and marginal bone loss (MBL) progression being of paramount importance. Progressive MBL undermines mechanical retention, predisposing implants to micromotion and jeopardizing their long-term survival. Accumulating evidence has revealed that homeostatic occlusion imbalance, characterized by excessive occlusal loading, aberrant occlusal contacts, and dysfunctional guidance, significantly increases the incidence of peri-implant bone loss, thereby disrupting biomechanical homeostasis. Therefore, this manuscript delineates the mechanistic role of steady-state occlusal imbalance in driving peri-implant MBL and proposes a homeostatic occlusion-based strategy for preventing and controlling such bone loss, aiming to enhance the long-term stability of dental implants.
Humans ; Dental Implants ; Homeostasis ; Dental Occlusion ; Alveolar Bone Loss/prevention & control* ; Biomechanical Phenomena

This study investigated a novel coronary knobby scoring balloon through finite element analysis (FEA) and in vitro anti-slippage testing, evaluating its dilation process under various vascular conditions and comparing it with other balloons. The FEA results indicated that in the cases of healthy artery and diseased artery with different stenosis rates, the stress on the vessels caused by the knobby scoring balloon was significantly smaller than that of the scoring balloon, and was close to that of the plain balloon. In vitro anti-slippage testing showed that the slippage distance of a plain balloon was 0.11±0.06 mm, and there was no slippage for knobby scoring balloon under nominal pressure. Knobby scoring balloon can effectively expand calcified lesion while providing anti-slippage function, and has a lower risk of vascular injury.
Finite Element Analysis ; Humans ; Angioplasty, Balloon, Coronary/instrumentation* ; Equipment Design ; Biomechanical Phenomena ; Coronary Vessels

The importance of gait assessment in the rehabilitation of cancer patients is gradually being recognized. However, quantitative analysis of balance ability in cancer patients is still limited. A total of 102 cancer patients meeting the inclusion criteria were recruited from Hefei Cancer Hospital, Chinese Academy of Sciences. Their balance ability was evaluated using the Berg Balance Scale (BBS). Gait data were collected by an electronic walkway and an IMU sensor system, including spatial-temporal and kinematic gait features such as step length, cadence, support time, and range of motion. Recursive feature elimination was used for feature selection. Ridge, Elastic Net, SVR, RF, and AdaBoost models were used to predict balance ability scores. Five-fold cross-validation was used to evaluate the performance of these models. Results show that the SVR model achieves the best performance with fifteen features (RMSE=3.22, R ²=0.91), followed by Ridge (RMSE=3.63, R ²=0.89). A method for evaluating balance ability based on gait features is proposed, providing a quantitative tool for personalized rehabilitation interventions in cancer patients.
Humans ; Postural Balance ; Neoplasms/rehabilitation* ; Gait ; Gait Analysis ; Biomechanical Phenomena ; Female

OBJECTIVES: To assess the biomechanical performance of a novel bridging plate for treating Rockwood III acromioclavicular joint dislocation. METHODS: A novel bridging plate structure was designed based on CT data from a patient with Rockwood type III acromioclavicular joint dislocation, and a finite element model of the bridging plate-acromioclavicular joint interaction was constructed. The stress and deformation characteristics and biomechanical compatibility of the plate under post-reduction, normal loading, and impact loading conditions were analyzed to evaluate its fixation mechanism and clinical advantages. RESULTS: The stiffness of the bridging system was 27.78 N/mm, close to that of acromioclavicular joint ligaments (26.05 N/mm) and meeting the requirements for flexible deformation. Under normal loading, the maximum stress in the bridging system was 88.29 MPa to sustain physiological activities; under impact loading, the maximum stress reached 480 MPa, and the cable underwent plastic deformation to dissipate energy and effectively buffer local stress concentrations, thereby reducing the risk of rigid bone fractures. The high-stress regions in the bone primarily occurred at the edges of the C1-C4 screw holes. The maximum bone stress was 0.762 MPa under normal loading and 5.963 MPa under impact loading, accounting for 2.86% and 1.66% of the corresponding bolt stresses, respectively. CONCLUSIONS The novel bridging plate is better adapted to biomechanical characteristics of the acromioclavicular joint compared to traditional internal fixation. This fixation system provides sufficient stability while allowing physiological micromotion to facilitate postoperative rehabilitation. Significant flexible deformation can occur at the connection between the fixation ring and the cable, and brittle materials should not be used in this region. The issue of stress concentration at the C1-C4 screw holes requires special attention in its clinical application.
Acromioclavicular Joint/surgery* ; Humans ; Bone Plates ; Biomechanical Phenomena ; Finite Element Analysis ; Joint Dislocations/surgery* ; Fracture Fixation, Internal/methods*