Applied Bionics and Biomechanics最新文献

Diabetic retinopathy (DR), a major cause of vision impairment, results from hyperglycemia-induced retinal microvascular damage. Current therapies mainly address symptoms rather than underlying mechanisms. Ginseng, a traditional medicinal herb with antioxidant and anti-inflammatory properties, may offer therapeutic benefits for DR. This study employed network pharmacology to identify bioactive compounds in ginseng and their potential molecular targets associated with DR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant enrichment in inflammation- and oxidative stress-related pathways, particularly the advanced glycation end product (AGE)-RAGE signaling pathway. A protein-protein interaction (PPI) network identified key targets, and molecular docking and dynamics simulations confirmed strong binding affinities between ginseng compounds and DR-related proteins. These findings suggest ginseng may modulate critical pathways involved in DR progression, offering potential as a natural therapeutic agent.

Objective: To analyze the effects of different hard pull actions on lumbar joint movement and dynamics in weightlifting and evaluate their contribution to the risk of lumbar spine injury.

Method: The study recruited eight national second level and above weightlifters as volunteers, and conducted detailed kinematic and dynamic analysis of different hard pull actions through exercise experiments and finite element analysis (FEA).

Result: The lumbar flexion angles of traditional hard pull and hexagonal barbell hard pull were 58° and 55°, respectively, while the lumbar flexion angle of straight leg hard pull was 90°. The first peak torque of straight leg hard pull was 893 N∙m, significantly higher than the traditional hard pull of 749 N∙m and the hexagonal barbell hard pull of 640 N∙m. In terms of stress distribution, the peak stress of straight leg hard pull at the L5 vertebral body was 997 MPa, and the peak stress of L5 trabecular bone was 3.3 MPa, both higher than traditional hard pull and hexagonal barbell hard pull. The peak stress of the lumbar intervertebral disc was also highest in straight leg tension, with the peak stress of the L4-5 lumbar intervertebral disc being 45.6 MPa.

Conclusion: Straight leg hard pull causes greater damage to the lumbar spine due to its larger lumbar flexion angle and higher peak stress. The damage to the L5 vertebral body during weightlifting is much higher than that of other lumbar vertebrae. Therefore, it is recommended to reduce straight leg hard pull during weightlifting training and strengthen protective measures for the L5 vertebral body to reduce lumbar spine injury.

Individuals with nontraumatic genu valgum (GV) may be at an increased risk of anterior cruciate ligament (ACL) injuries. This study investigates the impact of fatigue on lower limb biomechanics in individuals with GV compared to healthy controls. A total of eight female participants with GV and eight female healthy controls were recruited. All participants completed a running-induced fatigue protocol. Kinematic and kinetic data were collected, followed by statistical analysis using independent and paired-samples t-tests to compare between-group and within-group differences, respectively. The results demonstrated that compared to the control group, the fatigued GV group exhibited significantly greater hip flexion angles and hip flexion moments, hip internal rotation angles and hip internal rotation moments, knee flexion angles, knee internal rotation angles, and knee external rotation moments. Similarly, individuals with GV exhibited increased ankle plantarflexion angles, ankle dorsiflexion moments, ankle external rotation angles, and ankle external rotation moments. Moreover, the GV group displayed greater knee adduction angles, hip abduction angles, and ankle adduction angles than their healthy counterparts. Following fatigue, significant increases were observed in hip adduction angles, hip adduction moments, and hip flexion moments. Knee abduction angles, knee flexion angles, and knee abduction moments also increased, along with ankle eversion angles, ankle internal rotation angles, and ankle eversion moments. Furthermore, external rotation angles at both the hip and knee joints were notably elevated. During the stance phase of running, the fatigued GV group exhibited greater activation of the quadriceps and gastrocnemius muscles compared to the control group, whereas tibialis anterior (TA) activation decreased. Postfatigue, vastus lateralis (VL) activation further increased, whereas TA activation continued to decline relative to prefatigue levels. These findings underscore the importance of developing targeted exercise interventions to better assess the biomechanical characteristics and potential injury risks associated with GV.

Background: Percutaneous intramuscular septal radiofrequency ablation (PIMSRA) provi des an innovative alternative to septal myectomy (SM) and alcohol septal ablation (ASA). The precise segmentation of the interventricular septal is of paramount importance for the successful execution of the PIMSRA procedure. The study is based on the feasibility of applying the neural network-based method of UNETR model to the automatic segmentation of ventricular septal free wall structure in cardiac CT images of patients with HOCM and the three-dimensional reconstruction method based on visualization toolkit (VTK). Materials and Methods: The MedSAM-2, UNET and UNETR models were used to automatically segment the interventricular septal wall structure from 700 cardiac CT images of 23 patients. The image annotation tool was Labelme software, and the ratio of training set, test set, as well as validation set was 6:2:2. The higher Dice coefficient of the segmentation model was chosen to address the images, and the segmentation results were uesd to reconstruct in 3D with the metod of moving cubes. Results: Via training the UNETR segmentation model, when the parameter of batch and epoch were 8 and 32, respectively, the Dice coefficient of the interventricular septal-free wall structure test set is 0.89, which is higher than the Dice coefficient of 0.81 of the UNET model and 0.83 of the MedSAM-2 model. The model of UNETR was chosen to achieve the better segmentation results, and VTK three-dimensional reconstruction was performed based on the better segmentation results which is more closer to the real structure of heart. Conclusion: The results show that the segmentation method is feasible, and the three-dimensional reconstruction of the interventricular septal free wall structure by VTK based on the segmentation results is also feasible.

Background: Sandals are widely favored for their comfort; however, their open design may reduce foot support and compromise gait stability. Objective: This study examined the effects of various sandal strap configurations and walking speeds on spatiotemporal gait parameters and the integrated electromyographic (iEMG) activity of lower limb muscles. Methods: Twenty-four healthy adult males (age: 25.00 ± 1.22 years; mass: 71.50 ± 11.84 kg; height: 173.50 ± 3.50 cm) participated in this study. A two-way repeated-measures ANOVA was performed to assess the effects of three footwear conditions (barefoot, Crocs strapped, and Crocs strapless) across three walking speeds (1.2, 1.6, and 2.0 m/s). Gait outcomes included step length, step width, step frequency, peak plantar loading duration, and iEMG activity of key lower limb muscles: gluteus maximus (GM), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and lateral gastrocnemius (LG). Results: Footwear condition significantly affected step width (p < 0.05) and step frequency (p < 0.001). A significant interaction between footwear and walking speed was observed for peak plantar loading duration in both the forefoot and heel regions (p < 0.05). Additionally, significant differences in RF and GM iEMG activity were found between barefoot and strapped conditions (p < 0.05). Conclusions: Strapped sandals improve plantar load distribution and gait stability by regulating step frequency and reducing lower limb muscle activation, with these effects being more pronounced at higher walking speeds, particularly during forefoot and heel loading phases.

Background: Force sense reflects the efferent activity capacity of proprioception. Currently, methods for measuring force sense in the knee joint is lack. This study aims to validate a constructed test system and to explore the characteristics of force sense in patients with knee osteoarthritis (KOA). Methods: Seventy-five subjects were recruited: 30 for verifying the reliability of test system and exploring the impact of body mass index (BMI) and the striking force on force sense; 20 healthy adults and 25 KOA patients for the method application. The force sense test system comprised a self-designed force application apparatus and a wireless surface electromyography (sEMG) device (DELSYS Inc, USA). The reflex contraction latency of muscles was considered as the force sense. The intraclass correlation coefficient (ICC) was used to verify the reliability. Results: The reflex contraction latencies of biceps femoris (BF) was the shortest and ICC in the two tests is 0.950 (p < 0.001). No significant differences in force sense were found between different BMI groups (p=0.065), and there was no notable interaction between BMI and striking force (p=0.283). A significant difference in force sense was observed between different striking forces (p < 0.001). There were no significant differences in force sense of bilateral sides between healthy people and KOA patients (p=0.126, p=0.315). Conclusion: The force sense testing method established in this study is applicable for measuring knee joint force sense. BMI did not affect knee joint force sense but striking force did, and subjects with different BMI chose the same striking force; KOA did not influence the force sense of knee joint.

In response to the ever-increasing demand of upper limb rehabilitation training and function improvement, a novel arm rehabilitation robot with mobile platform, which can move on the table, is designed to facilitate the upper limbs strength training via the passive force field. The proposed robot provides three passive degrees of freedom (plane motion on the table and rotation around the vertical axis), which can fulfill the robot-aided trajectory training for upper limbs, such as shoulder, elbow, and wrist flexion/extension. Meanwhile, changed force field was established on the table via three elastic ropes. The user first connects the robot by the grab handle and arm support, then the screen displays the reference trajectory (RT) and notifies the user to manipulate the robot to draw the trajectory, the actual trajectory is calculated via the sensors and displayed to feed the user to adjust the muscular strength. In this paper, the reference trajectories, corresponding angular velocity of the wheels and the distribution of force field are analyzed via the dynamic modeling. Simulation studies are carried out to analyze the effectiveness of the theoretical model, kinematic performance, and distribution of force field. The path tracking simulation results showed that the peak error was 1.2 mm for the "∞" curve and 0.9 mm for the "O" curve. The force analysis results showed that the robot can generate the circinate force field and the maximum force of the whole workspace was 9.8 N with the elastic rigidity was 20 N/m. Furthermore, the maximum force was 11.02 N and the minimum force was 6.48 N when the robot moved along the of the circular path. These results demonstrate that the robot can generate appropriate force field to facilitate the motor training and paved the way to interventional therapy of the robot in the future. We will optimize the structure parameters and assemble a prototype to test the performance of the robot.

Objective: This study aimed to evaluate the plantar biomechanics in high-arched (HA) young runners after they performed a high-intensity (HI) ergometer exercise. Methods: Eighteen collegiate runners with HA feet (age = 19.9 ± 0.6 years, height = 179.4 ± 3.5 cm, weight = 69.3 ± 4.9 kg, arch height index [AHI] = 0.43 ± 0.04) were tested. The participants performed a 5-min HI ergometer exercise. Besides measuring heart rate (HR), blood pressure (BP), and ratings of perceived exertion (RPE), the plantar biomechanic features were assessed before and after exercise. Results: Postexercise, the participants exhibited a fatigue index (FI) of 87.6% ± 7.9%. The mean HR (HR_mean) corresponded to 81.1% ± 5.4% of maximum HR (HR_max). Notably, there was a significant drop (p < 0.001) in systolic BP (SBP) and diastolic BP (DBP) at the 10-min postexercise. The average RPE index was 17.3 ± 1.3. Specifically, the contact area of the hallux (T1) significantly increased (p < 0.05), while the contact area of toes 2-5 (T2-5) and the 5th metatarsal (M5) significantly decreased (p < 0.05). Plantar pressure significantly increased in T1 (p < 0.05), but significantly decreased in M5 and T2-5 (p < 0.05). The force-time integral (FTI) in the forefoot and vertical ground reaction force (VGRF) during heel fully struck and forefoot push off elevated, while the foot progression angle (FPA) significantly increased (p < 0.01). Conclusions: Our findings indicate that HI ergometer exercise has significant impacts on the biomechanic features of HA young runners. Specifically, we observed modifications in plantar area and pressure, FTI, and VGRF, especially in the medial arch and combined with outward rotation of the feet. These results can offer insights to inform future investigations on gait training interventions aimed at reducing the risk of lower extremity injuries in HA young runners.

Background: Diabetic retinopathy (DR) and diabetic cataract (DC) are two closely related microvascular complications of diabetes. Panax notoginseng, a plant from the Araliaceae family and genus Panax, is widely used in traditional Chinese medicine (TCM) due to its antioxidant, anti-inflammatory, and blood circulation-promoting properties. Recent studies suggest that drugs possessing anti-inflammatory, antioxidant, and blood circulation-promoting characteristics may have unexpected benefits in treating diabetic microvascular complications. This study employs network pharmacology to investigate the mechanisms by which P. notoginseng can treat DR and DC as comorbidities. Objective: The study aims to explore the active components and biological mechanisms of P. notoginseng in treating these comorbidities using network pharmacology and molecular docking. Methods: Components of P. notoginseng were identified through literature reviews and database queries. Active components were selected based on drug-like principles, and their targets were predicted using the principle of similarity. Disease-related genes were collected from OMIM and GeneCards and scored. Venn analysis identified target nodes, followed by protein-protein interaction (PPI) network analysis, gene ontology (GO) analysis, and KEGG pathway analysis. Topological algorithms analyzed the PPI network, and key nodes combined with other analysis results were utilized to construct a P. notoginseng-active component-gene-phenotype network using Cytoscape 3.9.1. Molecular docking on key genes, integrated with biological background, determined potential therapeutic targets against the diseases. Results: P. notoginseng contains eight active components and 234 potential gene targets. Network analysis showed that P. notoginseng can repair microvascular damage by influencing disease-related signaling pathways. Molecular docking indicated that four key targets (SRC, JAK2, IGF1R, and EGFR) effectively bind to the active components of P. notoginseng. Conclusion: These findings provide insights into the molecular-level action of P. notoginseng against these diseases. Overall, this study enhances our understanding of the potential of P. notoginseng in treating DR and DC as comorbidities and establishes a foundation for further research.

The integrity of the medial wall of the proximal femur is crucial for maintaining mechanical homeostasis. However, the impact of intertrochanteric fractures on the medial wall and the optimal diagnostic methodology remain unclear. We retrospectively analyzed CT data from 205 patients with intertrochanteric fractures. The lowest point of the medial fracture line was marked, and a standard coordinate system was established to record its spatial position. The association between AO, Evans, or Tang classification and different types of medial wall disruption was analyzed using Spearman correlation. The lowest point of the fracture line was located in the first quadrant of the proximal medial wall in 20 patients, with spatial coordinates of (6.44 ± 5.47, 6.14 ± 2.71). In 21 patients, it was in the second quadrant, with coordinates of (-7.23 ± 5.86, 8.31 ± 6.59). In 122 patients, it was in the third quadrant, with coordinates of (-9.59 ± 4.32, -24.43 ± 15.79), and in 42 patients, it was in the fourth quadrant, with coordinates of (8.18 ± 4.56, -18.20 ± 12.92). The Tang classification showed a stronger correlation with fracture instability (r = 0.40, p  < 0.001) compared to the AO (r = 0.32, p  < 0.001) and Evans (r = 0.38, p  < 0.001) classifications. The medial wall of the proximal femur is significantly compromised in intertrochanteric fractures, with varying mechanical stability depending on the fracture type. The Tang classification effectively differentiates these stability differences, providing valuable guidance for clinical practice.