The first metatarsophalangeal(MTP)joint plays a crucial role in foot biomechanics,particularly in weight-bearing activities such as walking and running.It is frequently affected by conditions like hallux valgus(HV)and...The first metatarsophalangeal(MTP)joint plays a crucial role in foot biomechanics,particularly in weight-bearing activities such as walking and running.It is frequently affected by conditions like hallux valgus(HV)and hallux rigidus,with HV impacting approximately 23%-35% of the population.This narrative review explores the embryology,anatomy,and biomechanics of the first MTP joint(MTPJ),highlighting its significance in maintaining foot stability and function.A comprehensive literature search was conducted using PubMed,Scopus,and Google Scholar,analyzing 50 relevant studies,including 12 clinical trials.The joint’s complex structure and mechanical demands make it susceptible to degenerative and structural disorders.Studies indicate that 25%-40%of individuals with HV experience significant pain and functional impairment,affecting mobility and quality of life.Biomechanical stress,abnormal gait patterns,and joint instability contribute to disease progression.Understanding the anatomical and biomechanical properties of the first MTPJ is essential for improving diagnostic and therapeutic approaches.Emerging surgical techniques,such as osteotomy and joint resurfacing,show promise in reducing recurrence rates and enhancing longterm outcomes.Further research is needed to refine minimally invasive interventions and optimize treatment strategies for first MTPJ disorders.展开更多
Pneumatic artificial muscles(PAMs)can generate multimodal movements,e.g.,linear contraction/extension,spiral torsion,and bending motions.Among these motions,contraction and extension movements can be achieved using li...Pneumatic artificial muscles(PAMs)can generate multimodal movements,e.g.,linear contraction/extension,spiral torsion,and bending motions.Among these motions,contraction and extension movements can be achieved using linear PAMs(LPAMs)designed to mimic human skeletal muscle.LPAMs have considerable potential for wearable applications and can be integrated into soft wearable robotic systems.Due to their inherent compliance,excellent human-robot interaction,safety,and low cost,LPAMs are considered potential alternatives as actuator components in the construction of wearable robots.This review presents a comprehensive overview of the bio-inspired design of LPAMs and their wearable applications.The biomechanics of human skeletal muscle,including anatomy,morphology,and biomechanical characterization,is analyzed to provide design inspirations for LPAMs and determine the assistance requirements of LPAM-based wearable robots.Herein,LPAMs are classified into four categories based on their structural shapes,including cylindrical-shaped muscles,flat-shaped muscles,fold-shaped muscles,and muscles with other shapes.In addition,this review provides an overview of the diverse physical interfaces utilized in wearable robots and presents a comparative analysis of the actuation characteristics of LPAMs and the assistance performance of LPAM-based wearable robots.This analysis was conducted in consideration of several key metrics,including the contraction ratio,maximum force,specific force,response frequency,assistive torque/bodyweight,and net metabolic cost.Finally,this review summarizes the ongoing challenges and future research directions.展开更多
As the core facility of offshore wind power systems,the structural safety of offshore booster stations directly impacts the stable operation of entire wind farms.With the global energy transition toward green and lowc...As the core facility of offshore wind power systems,the structural safety of offshore booster stations directly impacts the stable operation of entire wind farms.With the global energy transition toward green and lowcarbon goals,offshore wind power has emerged as a key renewable energy source,yet its booster stations face harsh marine environments,including persistent wave impacts,salt spray corrosion,and equipment-induced vibrations.Traditional monitoring methods relying on manual inspections and single-dimensional sensors suffer from critical limitations:low efficiency,poor real-time performance,and inability to capture millinewton-level stress fluctuations that signal early structural fatigue.To address these challenges,this study proposes a biomechanics-driven structural safety monitoring system integrated with deep learning.Inspired by biological stress-sensing mechanisms,the system deploys a distributedmulti-dimensional force sensor network to capture real-time stress distributions in key structural components.A hybrid convolutional neural network-radial basis function(CNN-RBF)model is developed:the CNN branch extracts spatiotemporal features from multi-source sensing data,while the RBF branch reconstructs the nonlinear stress field for accurate anomaly diagnosis.The three-tier architectural design—data layer(distributed sensor array),function layer(CNN-RBF modeling),and application layer(edge computing terminal)—enables a closedloop process from high-resolution data collection to real-time early warning,with data processing delay controlled within 200 ms.Experimental validation against traditional SOM-based systems demonstrates significant performance improvements:monitoring accuracy increased by 19.8%,efficiency by 23.4%,recall rate by 20.5%,and F1 score by 21.6%.Under extreme weather(e.g.,typhoons and winter storms),the system’s stability is 40% higher,with user satisfaction improving by 17.2%.The biomechanics-inspired sensor design enhances survival rates in salt fog(85.7%improvement)and dynamic loads,highlighting its robust engineering applicability for intelligent offshore wind farm maintenance.展开更多
We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve de...We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects.To test this,we established rabbit models of 30 mm sciatic nerve defects,and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells.We compared the tensile properties,electrophysiological function and morphology of the damaged nerve in each group.Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone,and produced similar results to those observed with the autograft.These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.展开更多
Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles（MAVs） design,we propose a comprehensive computational framework,whic...Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles（MAVs） design,we propose a comprehensive computational framework,which integrates aerodynamics,flight dynamics,vehicle stability and maneuverability.This framework consists of（1） a Navier-Stokes unsteady aerodynamic model;（2） a linear finite element model for structural dynamics;（3） a fluidstructure interaction（FSI） model for coupled flexible wing aerodynamics aeroelasticity;（4） a free-flying rigid body dynamic（RBD） model utilizing the Newtonian-Euler equations of 6DoF motion;and（5） flight simulator accounting for realistic wing-body morphology,flapping-wing and body kinematics,and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight.Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly.The present approach can support systematic analyses of bio- and bio-inspired flight.展开更多
The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies ov...The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.展开更多
AIM： To compare the corneal biomechanical outcomes at one year after laser in situ keratomileusis（LASIK） with the flaps created by Ziemer and Moria M2 microkeratome with 110 head and -20 blade.METHODS： Totally 100...AIM： To compare the corneal biomechanical outcomes at one year after laser in situ keratomileusis（LASIK） with the flaps created by Ziemer and Moria M2 microkeratome with 110 head and -20 blade.METHODS： Totally 100 eyes of 50 consecutive patients were enrolled in this prospective study and divided into two groups for corneal flaps created by Ziemer Femto LDV and Moria M2 microkeratome with 110 head and -20 blade.Corneal biomechanical properties including cornea resistance factor（CRF） and cornea hysteresis（CH） were measured before and 1,3,6,12 mo after surgery by ocular response analyzer.Central cornea thickness and corneal flap thickness were measured by optical coherence tomography.RESULTS： The ablation depth（P=0.693）,residual corneal thickness（P=0.453）,and postoperative corneal curvature（P=0.264） were not significant different between Ziemer group and Moria 110-20 group after surgery.The residual stromal bed thickness,corneal flap thickness,CH and CRF at 12 mo after surgery were significant different between Ziemer group and Moria 110-20 group（P〈0.01）; Ziemer group gained better corneal biomechanical results.The CRF and CH increased gradually from 1 to12 mo after surgery in Ziemer group,increased from 1 to 6 mo but decreased from 6 to 12 mo in Moria 110-20 group.Both CRF and CH at one year after surgery increased with the increasing of residual cornea thickness; pre-LASIK CRF,CRF also increased with residual stromal bed thickness,while CH decreased with the increasing of pre-LASIK intraocular pressure and cornea flap thickness（P〈0.01）.CONCLUSION： In one year follow-up,femtosecond laser can provide better cornea flaps with stable cornea biomechanics than mechanical microkeratome.展开更多
As an intriguing interdisciplinary research field, cell and molecular biomechanics is at the cutting edge of mechanics in general and biomechanics in particular. It has the potential to provide a quantitative understa...As an intriguing interdisciplinary research field, cell and molecular biomechanics is at the cutting edge of mechanics in general and biomechanics in particular. It has the potential to provide a quantitative understanding of how forces and deformation at tissue, cellular and molecular levels affect human health and disease. In this article, we review the recent advances in cell and molecular biomechanics, examine the available computational and experimental tools, and discuss important issues including protein deformation in mechanotransduction, cell deformation and constitutive behavior, cell adhesion and migration, and the associated models and theories. The opportunities and challenges in cell and molecular biomechanics are also discussed. We hope to provide readers a clear picture of the current status of this field, and to stimulate a broader interest in the applied mechanics community.展开更多
With the development of technology and the change of market demands,the trend in middle and high grade bicycle manufacturing is developed toward small-volume,multi-species,and customer-oriented production.Therefore,hu...With the development of technology and the change of market demands,the trend in middle and high grade bicycle manufacturing is developed toward small-volume,multi-species,and customer-oriented production.Therefore,human element should be fully considered in design so that the bicycle has the best cycling performance for the specific rider.Currently,customized design is difficult to achieve since feature parameters of the rider are not included in the design.The design of bicycle frame is the most important in bicycle design.The relative positions among the saddle,handlebar and central axis are defined as the bicycle three-pivot,they are the main parameters in bicycle frame design.In conventional bicycle design,frame parameters are merely relevant to bicycle types.On the basis of the principles of biomechanics and ergonomics knowledge,this paper presents a design method for bicycle three-pivot considering feature parameters of the rider by dynamic simulation.Firstly,a dynamic model of rider-bicycle system is built for a special rider,and a serial of simulation experiments is designed by uniform test method.Then,a mathematical model is built between the three-pivot position and the square of lower limb muscle stress by using simulation and regression analysis of the rider-bicycle system.The optimal three-pivot position parameters are obtained by setting the minimal of the square of the lower limb muscle stress as the objective.Therefore,the optimal parameters are gained for the specific rider.Finally,various results are gained for different riders based on the same design process.The function between feature parameters of the rider and the optimum three-pivot position parameters is built by regression.Bicycle design considering biomechanics can be divided into three main steps：calculating the three-pivot position,designing the geometrical structure of the bicycle frame and analyzing frame strength,and selecting appropriate parts and assembling the bicycle.Bicycle design considering biomechanics changes the conventional bicycle design and realizes customized design by considering human element in the design process.展开更多
The complex and variable nature of traumatic spinal cord inju- ry （SCI） presents a unique challenge for translational research. SCI is not bound by any demographic nor is it limited to specific injury biomechanics.
AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 m...AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon＇s capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements（n=5）. The remaining five treated eyes were prepared for histological examination.RESULTS：Compared to the untreated scleral strips,the genipin-crosslinked scleral strips showed that the ultimate stress and Young＇s modulus at 10% strain were increased by the amplitude of 130% and 303% respectively,ultimate strain was decreased by 24%. There had no α-smooth muscle actin（α-SMA）positive cells in control and treated sclera. Histologically,there was no sign of apoptosis in the sclera,choroid,and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area.CONCLUSION：Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera,with no α-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral,choroidal,and retinal cells,genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.展开更多
AIM：To compare the corneal biomechanics of Sj？gren＇s syndrome（SS） and non-SS dry eyes with Corneal Visualization Scheimpflug Technology（CorV is ST）.METHODS：Corneal biomechanics and tear film parameters, namely...AIM：To compare the corneal biomechanics of Sj？gren＇s syndrome（SS） and non-SS dry eyes with Corneal Visualization Scheimpflug Technology（CorV is ST）.METHODS：Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time（TBUT） and corneal staining score（CSS） were detected in 34 eyes of 34 dry eye patients with SS（SSDE group） and 34 dry eye subjects without SS（NSSDE group） using CorV is ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. RESULTS：The differences in age, sex, intraocular pressure（IOP） and central corneal thickness（CCT） were not significant between the two groups（P〉0.05）. The tear film parameters had significant differences between the SSDE group and NSSDE group（all P〈0.05）. Patients in the SSDE group had significantly lower A1-time and HC-time, but higher DA（P=0.01, 0.02, and 0.02, respectively） compared with the NSSDE group. In the SSDE group, DA was negatively correlated with TBUT（rho=-0.38, P=0.03）; HC-time was negatively correlated with CSS（rho=-0.43, P=0.02）. In the NSSDE group, HC-time was again negatively correlated with CSS（rho=-0.39, P=0.02）.CONCLUSION：There are differences in corneal biomechanical properties between SSDE and NSSDE. The cornea of SSDE tends to show less ＂stiffness＂, as seen by a significantly shorter A1-time and HC-time, but larger DA, compared with the cornea of NSSDE. Biomechanical parameters can be influenced by different tear film parameters in both groups.展开更多
AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent t...AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent the FS-LASIK from April 2022 to November 2022 were included.They were divided into three groups according to the ratio of residual corneal stroma thickness/corneal thickness(RCST/CT):Group I(50%≤RCST/CT<55%,63 eyes of 32 patients),Group II(55%≤RCST/CT<60%,67 eyes of 34 patients),and Group III(RCST/CT≥60%,67 eyes of 34 patients).The intraocular pressure(IOP),corneal compensated IOP(IOPcc),corneal hysteresis(CH)and corneal resistance factor(CRF)were measured immediately,1,and 3mo postoperatively by ocular response analyzer(ORA)and the posterior elevation difference(PED)was measured by Pentacam.RESULTS:After operation,IOP,CH,CRF,and PED were statistically different among the three groups(F=12.99,31.148,23.998,all P<0.0001).There was no statistically significant difference in IOPcc among the three groups(F=0.603,P>0.05).The IOP,IOPcc,CH,and CRF were statistical changed after surgery(F=699.635,104.125,308.474,640.145,all P<0.0001).The PED of Group I was significantly higher than that of Group II(P<0.05),and Group II was significantly higher than that of Group III(P<0.05).The PED value of 3mo after surgery decreased in each group compared with 1mo after surgery,but there was no statistical difference(Group I:t=0.82,P=0.41;Group II:t=0.17,P=0.87;Group III:t=1.35,P=0.18).The correlation analysis of corneal biomechanical parameter changes with PED at 1mo and 3mo after surgery showed thatΔIOP,ΔIOPcc,ΔCH,andΔCRF were not correlated with PED value in three groups(P>0.05).CONCLUSION:The smaller the RCST/CT,the greater effect on corneal biomechanics and posterior surface elevation.There is no correlation between changes in corneal biomechanics and posterior corneal surface elevation in the range of RCST/CT≥50%.展开更多
Accumulating evidence indicates that glaucoma is a multifactorial neurodegenerative disease characterized by the loss of retinal ganglion cells （RGC）, resulting in gradual and progressive permanent loss of vision. R...Accumulating evidence indicates that glaucoma is a multifactorial neurodegenerative disease characterized by the loss of retinal ganglion cells （RGC）, resulting in gradual and progressive permanent loss of vision. Reducing intraocular pressure （IOP） remains the only proven method for preventing and delaying the progression of glaucomatous visual impairment. However, the specific role of IOP in optic nerve injury remains controversial, and little is known about the biomechanical mechanism by which elevated IOP leads to the loss of RGC. Published studies suggest that the biomechanical properties of the sclera and scleral lamina cribrosa determine the biomechanical changes of optic nerve head, and play an important role in the pathologic process of loss of RGC and optic nerve damage. This review focuses on the current understanding of biomechanics of sclera in glaucoma and provides an overview of the possible interactions between the sclera and IOP. Treatments and interventions aimed at the sclera are also discussed.展开更多
An accurate finite element （ FE ） model of the human middle ear can provide better understanding of the mechanics of middle ear, and can be used for aiding the design of the implantable middle ear hearing devices. I...An accurate finite element （ FE ） model of the human middle ear can provide better understanding of the mechanics of middle ear, and can be used for aiding the design of the implantable middle ear hearing devices. In this paper, a threedimensional （3D） FE model of the human middle ear was constructed, including the tympanic membrane, ossicular bones, and middle ear suspensory ligaments/museles. This model was constructed based on a complete set of computerized tomography section images of a healthy volunteer＇s left ear by reverse engineering technology. The validity of this model was confirmed by comparing the motions of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones. The result shows that the model is reasonable in predicting the biomechanics of the human middle ear.展开更多
To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the ...To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the quadratic sum of rider lower limb muscles stresses is presented as the evaluation criterion of muscle fatigue.By taking the criterion as the objective function, the relative positions of three pivot points of frame are optimized to ensure that the frame structural parameters match the stature o...展开更多
Background: Osteoarthritis is a widespread highly painful disabling age-related disease with no known cure. Although novel strategies for ameliorating osteoarthritic damage abound, it is likely that none will be succe...Background: Osteoarthritis is a widespread highly painful disabling age-related disease with no known cure. Although novel strategies for ameliorating osteoarthritic damage abound, it is likely that none will be successful over time if the entire spectrum of the disease and the effects of joint biomechanics on joint tissues are not carefully considered. Objectives: 1) To detail the structure of healthy articular cartilage, the key tissue affected by osteoarthritis. 2) To detail what aspects of cartilage damage best characterize osteoarthritis. 3) To consider the role of biomechanical factors in developing solutions to treat osteoarthritic joint damage. Methods: Literature sources from 1980 onwards that have contributed to our knowledge of the topics relevant to this paper were accessed and retrieved. The data were categorized into four predominant themes and conclusions about the state of our knowledge and future directives were formulated. Conclusions: Osteoarthritis prevalence remains high, and a cure appears elusive. A rich body of data has helped us to better understand the key tissue involved, and suggests a repair process might be feasible, if the basic collective information on the role of biomechanics in mediating or moderating articular cartilage integrity and function is forthcoming.展开更多
AIM:To compare intraocular pressure(IOP)measurements before and after laser in situ keratomileusis(LASIK)with a femtosecond laser for flap creation using ocular response analyzer(ORA)and Goldmann applanation tonometry...AIM:To compare intraocular pressure(IOP)measurements before and after laser in situ keratomileusis(LASIK)with a femtosecond laser for flap creation using ocular response analyzer(ORA)and Goldmann applanation tonometry,and to identify factors that may influence the preoperative and postoperative IOP.METHODS:A prospective study conducted on myopic patients who underwent LASIK using a femtosecond laser for flap fashioning.Enrolled patients were evaluated preoperatively,6 wk and 3 mo postoperatively for manifest refraction(MR),keratometric(K)readings and central corneal thickness(CCT)using a scheimpflug-based topography.Corneal resistance factor(CRF),corneal hysteresis(CH),Goldmann correlated IOP(IOPg)and corneal compensated IOP(IOPcc)were measured using ORA besides IOP assessment by Goldman applanation tonometry(GAT).RESULTS:There was a statistically significant decrease in measures of IOPg by 3.35±0.83 mm Hg,followed by GAT which decreased by 2.2±0.44 mm Hg,and the least affected by operation was IOPcc which decreased only by 0.87±0.1 mm Hg after 6 wk.After 3 mo follow up there was a statistically significant decrease in IOPcc which decreased only by 0.76±0.4 mm Hg,followed by IOP GAT by 1.6±0.5 mm Hg,and the most affected by operation was IOPg which decreased by 2.3±0.3 mm Hg.Correspondingly,there was a statistically significant decrease in CH and CRF after 6 wk and 3 mo.At 3 mo,the preoperative MR and preoperative GAT were prominent significant predictors of the postoperative GAT changes.The prediction equation was subsumed.CONCLUSION:IOP measurements and corneal biomechanical factors reduce significantly after LASIK with a femtosecond laser for flap creation.The IOPcc values are less influenced by changes in corneal properties than IOPg and GAT,indicating that IOPcc may provide the most reliable measurement of IOP after this procedure.展开更多
Background:Evaluation of corneal biomechanical properties 3 months after using rigid gas permeable(RGP)contact lenses in keratoconus.Methods:In this prospective trial study,cases were 32 keratoconic eyes with no histo...Background:Evaluation of corneal biomechanical properties 3 months after using rigid gas permeable(RGP)contact lenses in keratoconus.Methods:In this prospective trial study,cases were 32 keratoconic eyes with no history of RGP lens wear.All eyes were examined with the Ocular Response Analyzer(ORA)and the Corneal Visualization Scheimpflug Technology(CORVIS-ST)to measure corneal hysteresis(CH),corneal resistance factor(CRF),deformation amplitude(DA),applanation velocity(AV)1 and 2,applanation length(AL)1 and 2,and peak distance before and 3 months after fitting aspheric RGP lenses.The effect of the correlation between contralateral eyes and maximum keratometry were controlled for in the analysis.Results were compared using repeated measures analysis of covariance.Results:At 3 months,neither the increases in mean CH(0.14±2.77 mm Hg,P=0.789),CRF(0.41±4.35 mm Hg,P=0.612),AV1(0.03±0.17 m/s,P=0.301),AV2(0.11±0.59 m/s,P=0.299),AL1(0.44±1.56 m/s,P=0.118),AL2(1.16±5.06 m/s,P=0.211),and peak distance(0.19±1.29 m/s,P=0.409),nor the decrease in mean DA(0.03±0.17 mm,P=0.402)was statistically significant.Conclusions:Results in our series of patients indicated that 3 months of RGP lens wear had no significant impact on corneal biomechanics,and perhaps non progression of keratoconus.Therefore,RGP lenses can be regarded safe and appropriate in keratoconic patients.展开更多
文摘The first metatarsophalangeal(MTP)joint plays a crucial role in foot biomechanics,particularly in weight-bearing activities such as walking and running.It is frequently affected by conditions like hallux valgus(HV)and hallux rigidus,with HV impacting approximately 23%-35% of the population.This narrative review explores the embryology,anatomy,and biomechanics of the first MTP joint(MTPJ),highlighting its significance in maintaining foot stability and function.A comprehensive literature search was conducted using PubMed,Scopus,and Google Scholar,analyzing 50 relevant studies,including 12 clinical trials.The joint’s complex structure and mechanical demands make it susceptible to degenerative and structural disorders.Studies indicate that 25%-40%of individuals with HV experience significant pain and functional impairment,affecting mobility and quality of life.Biomechanical stress,abnormal gait patterns,and joint instability contribute to disease progression.Understanding the anatomical and biomechanical properties of the first MTPJ is essential for improving diagnostic and therapeutic approaches.Emerging surgical techniques,such as osteotomy and joint resurfacing,show promise in reducing recurrence rates and enhancing longterm outcomes.Further research is needed to refine minimally invasive interventions and optimize treatment strategies for first MTPJ disorders.
基金supported by the National Natural Science Foundation of China(No.52475067).
文摘Pneumatic artificial muscles(PAMs)can generate multimodal movements,e.g.,linear contraction/extension,spiral torsion,and bending motions.Among these motions,contraction and extension movements can be achieved using linear PAMs(LPAMs)designed to mimic human skeletal muscle.LPAMs have considerable potential for wearable applications and can be integrated into soft wearable robotic systems.Due to their inherent compliance,excellent human-robot interaction,safety,and low cost,LPAMs are considered potential alternatives as actuator components in the construction of wearable robots.This review presents a comprehensive overview of the bio-inspired design of LPAMs and their wearable applications.The biomechanics of human skeletal muscle,including anatomy,morphology,and biomechanical characterization,is analyzed to provide design inspirations for LPAMs and determine the assistance requirements of LPAM-based wearable robots.Herein,LPAMs are classified into four categories based on their structural shapes,including cylindrical-shaped muscles,flat-shaped muscles,fold-shaped muscles,and muscles with other shapes.In addition,this review provides an overview of the diverse physical interfaces utilized in wearable robots and presents a comparative analysis of the actuation characteristics of LPAMs and the assistance performance of LPAM-based wearable robots.This analysis was conducted in consideration of several key metrics,including the contraction ratio,maximum force,specific force,response frequency,assistive torque/bodyweight,and net metabolic cost.Finally,this review summarizes the ongoing challenges and future research directions.
基金supported by the Science and Technology Project of China Huaneng Group Co.,Ltd.Research on Key Technologies for Monitoring and Protection of Offshore Wind Power Underwater Equipment(HNKJ21-H40).
文摘As the core facility of offshore wind power systems,the structural safety of offshore booster stations directly impacts the stable operation of entire wind farms.With the global energy transition toward green and lowcarbon goals,offshore wind power has emerged as a key renewable energy source,yet its booster stations face harsh marine environments,including persistent wave impacts,salt spray corrosion,and equipment-induced vibrations.Traditional monitoring methods relying on manual inspections and single-dimensional sensors suffer from critical limitations:low efficiency,poor real-time performance,and inability to capture millinewton-level stress fluctuations that signal early structural fatigue.To address these challenges,this study proposes a biomechanics-driven structural safety monitoring system integrated with deep learning.Inspired by biological stress-sensing mechanisms,the system deploys a distributedmulti-dimensional force sensor network to capture real-time stress distributions in key structural components.A hybrid convolutional neural network-radial basis function(CNN-RBF)model is developed:the CNN branch extracts spatiotemporal features from multi-source sensing data,while the RBF branch reconstructs the nonlinear stress field for accurate anomaly diagnosis.The three-tier architectural design—data layer(distributed sensor array),function layer(CNN-RBF modeling),and application layer(edge computing terminal)—enables a closedloop process from high-resolution data collection to real-time early warning,with data processing delay controlled within 200 ms.Experimental validation against traditional SOM-based systems demonstrates significant performance improvements:monitoring accuracy increased by 19.8%,efficiency by 23.4%,recall rate by 20.5%,and F1 score by 21.6%.Under extreme weather(e.g.,typhoons and winter storms),the system’s stability is 40% higher,with user satisfaction improving by 17.2%.The biomechanics-inspired sensor design enhances survival rates in salt fog(85.7%improvement)and dynamic loads,highlighting its robust engineering applicability for intelligent offshore wind farm maintenance.
基金supported by the Science and Technology Development Plan Project Fund of Jilin Province in China,No.20110492
文摘We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects.To test this,we established rabbit models of 30 mm sciatic nerve defects,and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells.We compared the tensile properties,electrophysiological function and morphology of the damaged nerve in each group.Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone,and produced similar results to those observed with the autograft.These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.
基金supported by a PRESTO-JST program,the Grant-in-Aid for Scientific Research JSPS.Japan(18656056 and 18100002).
文摘Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles（MAVs） design,we propose a comprehensive computational framework,which integrates aerodynamics,flight dynamics,vehicle stability and maneuverability.This framework consists of（1） a Navier-Stokes unsteady aerodynamic model;（2） a linear finite element model for structural dynamics;（3） a fluidstructure interaction（FSI） model for coupled flexible wing aerodynamics aeroelasticity;（4） a free-flying rigid body dynamic（RBD） model utilizing the Newtonian-Euler equations of 6DoF motion;and（5） flight simulator accounting for realistic wing-body morphology,flapping-wing and body kinematics,and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight.Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly.The present approach can support systematic analyses of bio- and bio-inspired flight.
基金Supported by A Research fellowship from the faculty of Medicine,Westphalian Wilhelms University Muenster to Domnick C
文摘The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.
文摘AIM： To compare the corneal biomechanical outcomes at one year after laser in situ keratomileusis（LASIK） with the flaps created by Ziemer and Moria M2 microkeratome with 110 head and -20 blade.METHODS： Totally 100 eyes of 50 consecutive patients were enrolled in this prospective study and divided into two groups for corneal flaps created by Ziemer Femto LDV and Moria M2 microkeratome with 110 head and -20 blade.Corneal biomechanical properties including cornea resistance factor（CRF） and cornea hysteresis（CH） were measured before and 1,3,6,12 mo after surgery by ocular response analyzer.Central cornea thickness and corneal flap thickness were measured by optical coherence tomography.RESULTS： The ablation depth（P=0.693）,residual corneal thickness（P=0.453）,and postoperative corneal curvature（P=0.264） were not significant different between Ziemer group and Moria 110-20 group after surgery.The residual stromal bed thickness,corneal flap thickness,CH and CRF at 12 mo after surgery were significant different between Ziemer group and Moria 110-20 group（P〈0.01）; Ziemer group gained better corneal biomechanical results.The CRF and CH increased gradually from 1 to12 mo after surgery in Ziemer group,increased from 1 to 6 mo but decreased from 6 to 12 mo in Moria 110-20 group.Both CRF and CH at one year after surgery increased with the increasing of residual cornea thickness; pre-LASIK CRF,CRF also increased with residual stromal bed thickness,while CH decreased with the increasing of pre-LASIK intraocular pressure and cornea flap thickness（P〈0.01）.CONCLUSION： In one year follow-up,femtosecond laser can provide better cornea flaps with stable cornea biomechanics than mechanical microkeratome.
基金supported by the National Heart,Lung,and Blood Institute,National Institutes of Health,as a Program of Excellence in Nanotechnology Award,N01 HV-08234,to Gang Baothe support from the National Natural Science Foundation of China through Grant Nos.10872115,11025208 and 10732050
文摘As an intriguing interdisciplinary research field, cell and molecular biomechanics is at the cutting edge of mechanics in general and biomechanics in particular. It has the potential to provide a quantitative understanding of how forces and deformation at tissue, cellular and molecular levels affect human health and disease. In this article, we review the recent advances in cell and molecular biomechanics, examine the available computational and experimental tools, and discuss important issues including protein deformation in mechanotransduction, cell deformation and constitutive behavior, cell adhesion and migration, and the associated models and theories. The opportunities and challenges in cell and molecular biomechanics are also discussed. We hope to provide readers a clear picture of the current status of this field, and to stimulate a broader interest in the applied mechanics community.
基金supported by Tianjin Municipal Special Fund Project for Technology Innovation of China(Grant No.10FDZDGX00500),and Tianjin Municipal Key Laboratory of Advanced Manufacturing Technology and Equipment of Tianjin University of China
文摘With the development of technology and the change of market demands,the trend in middle and high grade bicycle manufacturing is developed toward small-volume,multi-species,and customer-oriented production.Therefore,human element should be fully considered in design so that the bicycle has the best cycling performance for the specific rider.Currently,customized design is difficult to achieve since feature parameters of the rider are not included in the design.The design of bicycle frame is the most important in bicycle design.The relative positions among the saddle,handlebar and central axis are defined as the bicycle three-pivot,they are the main parameters in bicycle frame design.In conventional bicycle design,frame parameters are merely relevant to bicycle types.On the basis of the principles of biomechanics and ergonomics knowledge,this paper presents a design method for bicycle three-pivot considering feature parameters of the rider by dynamic simulation.Firstly,a dynamic model of rider-bicycle system is built for a special rider,and a serial of simulation experiments is designed by uniform test method.Then,a mathematical model is built between the three-pivot position and the square of lower limb muscle stress by using simulation and regression analysis of the rider-bicycle system.The optimal three-pivot position parameters are obtained by setting the minimal of the square of the lower limb muscle stress as the objective.Therefore,the optimal parameters are gained for the specific rider.Finally,various results are gained for different riders based on the same design process.The function between feature parameters of the rider and the optimum three-pivot position parameters is built by regression.Bicycle design considering biomechanics can be divided into three main steps：calculating the three-pivot position,designing the geometrical structure of the bicycle frame and analyzing frame strength,and selecting appropriate parts and assembling the bicycle.Bicycle design considering biomechanics changes the conventional bicycle design and realizes customized design by considering human element in the design process.
文摘The complex and variable nature of traumatic spinal cord inju- ry （SCI） presents a unique challenge for translational research. SCI is not bound by any demographic nor is it limited to specific injury biomechanics.
基金Supported by Guangdong Province Science and Technology Projects(No.2007B031002001)
文摘AIM：To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS：Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon＇s capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements（n=5）. The remaining five treated eyes were prepared for histological examination.RESULTS：Compared to the untreated scleral strips,the genipin-crosslinked scleral strips showed that the ultimate stress and Young＇s modulus at 10% strain were increased by the amplitude of 130% and 303% respectively,ultimate strain was decreased by 24%. There had no α-smooth muscle actin（α-SMA）positive cells in control and treated sclera. Histologically,there was no sign of apoptosis in the sclera,choroid,and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area.CONCLUSION：Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera,with no α-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral,choroidal,and retinal cells,genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.
基金Supported by the National Natural Science Foundation of China(No.81070755)
文摘AIM：To compare the corneal biomechanics of Sj？gren＇s syndrome（SS） and non-SS dry eyes with Corneal Visualization Scheimpflug Technology（CorV is ST）.METHODS：Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time（TBUT） and corneal staining score（CSS） were detected in 34 eyes of 34 dry eye patients with SS（SSDE group） and 34 dry eye subjects without SS（NSSDE group） using CorV is ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. RESULTS：The differences in age, sex, intraocular pressure（IOP） and central corneal thickness（CCT） were not significant between the two groups（P〉0.05）. The tear film parameters had significant differences between the SSDE group and NSSDE group（all P〈0.05）. Patients in the SSDE group had significantly lower A1-time and HC-time, but higher DA（P=0.01, 0.02, and 0.02, respectively） compared with the NSSDE group. In the SSDE group, DA was negatively correlated with TBUT（rho=-0.38, P=0.03）; HC-time was negatively correlated with CSS（rho=-0.43, P=0.02）. In the NSSDE group, HC-time was again negatively correlated with CSS（rho=-0.39, P=0.02）.CONCLUSION：There are differences in corneal biomechanical properties between SSDE and NSSDE. The cornea of SSDE tends to show less ＂stiffness＂, as seen by a significantly shorter A1-time and HC-time, but larger DA, compared with the cornea of NSSDE. Biomechanical parameters can be influenced by different tear film parameters in both groups.
文摘AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent the FS-LASIK from April 2022 to November 2022 were included.They were divided into three groups according to the ratio of residual corneal stroma thickness/corneal thickness(RCST/CT):Group I(50%≤RCST/CT<55%,63 eyes of 32 patients),Group II(55%≤RCST/CT<60%,67 eyes of 34 patients),and Group III(RCST/CT≥60%,67 eyes of 34 patients).The intraocular pressure(IOP),corneal compensated IOP(IOPcc),corneal hysteresis(CH)and corneal resistance factor(CRF)were measured immediately,1,and 3mo postoperatively by ocular response analyzer(ORA)and the posterior elevation difference(PED)was measured by Pentacam.RESULTS:After operation,IOP,CH,CRF,and PED were statistically different among the three groups(F=12.99,31.148,23.998,all P<0.0001).There was no statistically significant difference in IOPcc among the three groups(F=0.603,P>0.05).The IOP,IOPcc,CH,and CRF were statistical changed after surgery(F=699.635,104.125,308.474,640.145,all P<0.0001).The PED of Group I was significantly higher than that of Group II(P<0.05),and Group II was significantly higher than that of Group III(P<0.05).The PED value of 3mo after surgery decreased in each group compared with 1mo after surgery,but there was no statistical difference(Group I:t=0.82,P=0.41;Group II:t=0.17,P=0.87;Group III:t=1.35,P=0.18).The correlation analysis of corneal biomechanical parameter changes with PED at 1mo and 3mo after surgery showed thatΔIOP,ΔIOPcc,ΔCH,andΔCRF were not correlated with PED value in three groups(P>0.05).CONCLUSION:The smaller the RCST/CT,the greater effect on corneal biomechanics and posterior surface elevation.There is no correlation between changes in corneal biomechanics and posterior corneal surface elevation in the range of RCST/CT≥50%.
基金Supported by National Natural Science Foundation of China(No.81370913)
文摘Accumulating evidence indicates that glaucoma is a multifactorial neurodegenerative disease characterized by the loss of retinal ganglion cells （RGC）, resulting in gradual and progressive permanent loss of vision. Reducing intraocular pressure （IOP） remains the only proven method for preventing and delaying the progression of glaucomatous visual impairment. However, the specific role of IOP in optic nerve injury remains controversial, and little is known about the biomechanical mechanism by which elevated IOP leads to the loss of RGC. Published studies suggest that the biomechanical properties of the sclera and scleral lamina cribrosa determine the biomechanical changes of optic nerve head, and play an important role in the pathologic process of loss of RGC and optic nerve damage. This review focuses on the current understanding of biomechanics of sclera in glaucoma and provides an overview of the possible interactions between the sclera and IOP. Treatments and interventions aimed at the sclera are also discussed.
基金National Natural Science Foundation of China ( No. 10772121)Med-Science Cross Research Foundation of Shanghai Jiaotong University, China(No.YG2007MS14)
文摘An accurate finite element （ FE ） model of the human middle ear can provide better understanding of the mechanics of middle ear, and can be used for aiding the design of the implantable middle ear hearing devices. In this paper, a threedimensional （3D） FE model of the human middle ear was constructed, including the tympanic membrane, ossicular bones, and middle ear suspensory ligaments/museles. This model was constructed based on a complete set of computerized tomography section images of a healthy volunteer＇s left ear by reverse engineering technology. The validity of this model was confirmed by comparing the motions of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones. The result shows that the model is reasonable in predicting the biomechanics of the human middle ear.
基金Supported by Tianjin Science and Technology Development Project (No.043186211)Tianjin Key Laboratory of Advanced Manufacturing Technology and Equipment
文摘To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the quadratic sum of rider lower limb muscles stresses is presented as the evaluation criterion of muscle fatigue.By taking the criterion as the objective function, the relative positions of three pivot points of frame are optimized to ensure that the frame structural parameters match the stature o...
文摘Background: Osteoarthritis is a widespread highly painful disabling age-related disease with no known cure. Although novel strategies for ameliorating osteoarthritic damage abound, it is likely that none will be successful over time if the entire spectrum of the disease and the effects of joint biomechanics on joint tissues are not carefully considered. Objectives: 1) To detail the structure of healthy articular cartilage, the key tissue affected by osteoarthritis. 2) To detail what aspects of cartilage damage best characterize osteoarthritis. 3) To consider the role of biomechanical factors in developing solutions to treat osteoarthritic joint damage. Methods: Literature sources from 1980 onwards that have contributed to our knowledge of the topics relevant to this paper were accessed and retrieved. The data were categorized into four predominant themes and conclusions about the state of our knowledge and future directives were formulated. Conclusions: Osteoarthritis prevalence remains high, and a cure appears elusive. A rich body of data has helped us to better understand the key tissue involved, and suggests a repair process might be feasible, if the basic collective information on the role of biomechanics in mediating or moderating articular cartilage integrity and function is forthcoming.
文摘AIM:To compare intraocular pressure(IOP)measurements before and after laser in situ keratomileusis(LASIK)with a femtosecond laser for flap creation using ocular response analyzer(ORA)and Goldmann applanation tonometry,and to identify factors that may influence the preoperative and postoperative IOP.METHODS:A prospective study conducted on myopic patients who underwent LASIK using a femtosecond laser for flap fashioning.Enrolled patients were evaluated preoperatively,6 wk and 3 mo postoperatively for manifest refraction(MR),keratometric(K)readings and central corneal thickness(CCT)using a scheimpflug-based topography.Corneal resistance factor(CRF),corneal hysteresis(CH),Goldmann correlated IOP(IOPg)and corneal compensated IOP(IOPcc)were measured using ORA besides IOP assessment by Goldman applanation tonometry(GAT).RESULTS:There was a statistically significant decrease in measures of IOPg by 3.35±0.83 mm Hg,followed by GAT which decreased by 2.2±0.44 mm Hg,and the least affected by operation was IOPcc which decreased only by 0.87±0.1 mm Hg after 6 wk.After 3 mo follow up there was a statistically significant decrease in IOPcc which decreased only by 0.76±0.4 mm Hg,followed by IOP GAT by 1.6±0.5 mm Hg,and the most affected by operation was IOPg which decreased by 2.3±0.3 mm Hg.Correspondingly,there was a statistically significant decrease in CH and CRF after 6 wk and 3 mo.At 3 mo,the preoperative MR and preoperative GAT were prominent significant predictors of the postoperative GAT changes.The prediction equation was subsumed.CONCLUSION:IOP measurements and corneal biomechanical factors reduce significantly after LASIK with a femtosecond laser for flap creation.The IOPcc values are less influenced by changes in corneal properties than IOPg and GAT,indicating that IOPcc may provide the most reliable measurement of IOP after this procedure.
文摘Background:Evaluation of corneal biomechanical properties 3 months after using rigid gas permeable(RGP)contact lenses in keratoconus.Methods:In this prospective trial study,cases were 32 keratoconic eyes with no history of RGP lens wear.All eyes were examined with the Ocular Response Analyzer(ORA)and the Corneal Visualization Scheimpflug Technology(CORVIS-ST)to measure corneal hysteresis(CH),corneal resistance factor(CRF),deformation amplitude(DA),applanation velocity(AV)1 and 2,applanation length(AL)1 and 2,and peak distance before and 3 months after fitting aspheric RGP lenses.The effect of the correlation between contralateral eyes and maximum keratometry were controlled for in the analysis.Results were compared using repeated measures analysis of covariance.Results:At 3 months,neither the increases in mean CH(0.14±2.77 mm Hg,P=0.789),CRF(0.41±4.35 mm Hg,P=0.612),AV1(0.03±0.17 m/s,P=0.301),AV2(0.11±0.59 m/s,P=0.299),AL1(0.44±1.56 m/s,P=0.118),AL2(1.16±5.06 m/s,P=0.211),and peak distance(0.19±1.29 m/s,P=0.409),nor the decrease in mean DA(0.03±0.17 mm,P=0.402)was statistically significant.Conclusions:Results in our series of patients indicated that 3 months of RGP lens wear had no significant impact on corneal biomechanics,and perhaps non progression of keratoconus.Therefore,RGP lenses can be regarded safe and appropriate in keratoconic patients.
