Background:Segment coordination variability(CV)is a movement pattern associated with running-related injuries.It can also be adversely affected by a prolonged run.However,research on this topic is currently limited.Th...Background:Segment coordination variability(CV)is a movement pattern associated with running-related injuries.It can also be adversely affected by a prolonged run.However,research on this topic is currently limited.The purpose of this study was to investigate the effects of a prolonged run on segment CV and vertical loading rates during a treadmill half marathon.Methods:Fifteen healthy runners ran a half marathon on an instrumental treadmill in a biomechanical laboratory.Synchronized kinematic and kinetic data were collected every 2 km(from 2 km until 20 km),and the data were processed by musculoskeletal modeling.Segment CVs were computed from the angle-angle plots of selected pelvis-thigh,thigh-shank,and shank-rearfoot couplings using a modified vector coding technique.The loading rate of vertical ground reaction force was also calculated.A one-way MANOVA with repeated measures was performed on each of the outcome variables to examine the main effect of running mileage.Results:Significant effects of running mileage were found on segment CVs(p≤0.010)but not on loading rate(p=0.881).Notably,during the early stance phase,the CV of pelvis frontal thigh frontal was significantly increased at 20 km compared with the CV at 8 km(g=0.59,p=0.022).The CV of shank transverse vs.rearfoot frontal decreased from 2 km to 8 km(g=0.30,p=0.020)but then significantly increased at both 18 km(g=0.05,p<0.001)and 20 km(g=0.36,p<0.001).Conclusion:At the early stance,runners maintained stable CVs on the sagittal plane,which could explain the unchanged loading rate throughout the half marathon.However,increased CVs on the frontal/transverse plane may be an early sign of fatigue and indicative of possible injury risk.Further studies are necessary for conclusive statements in this regard.展开更多
The methodological quality of subject-specific finite element analysis papers depends on the rigor of the study design and detailed description of key elements,while assessment instruments are often confined to clinic...The methodological quality of subject-specific finite element analysis papers depends on the rigor of the study design and detailed description of key elements,while assessment instruments are often confined to clinical trials or quasi-experiments.This study aims to present an instrument for methodological quality assessment of singlesubject finite element analysis used in computational orthopaedics(MQSSFE).Based upon existing instruments and relevant review papers,a pilot version was developed consisting of 37 items with 6 domains,including study design and presentation of findings,subject recruitment,model reconstruction and configuration,boundary and loading conditions(simulation),model verification and validation,and model assumption and validity.We interviewed four experts in the field to assess the face validity and refined the instrument.The instrument was tested for interrater reliability among two assessors on nine finite element study papers.Also,the criterion validity was evaluated by comparing the similarity of the MQSSFE and the modified Down and Black instrument.The intraclass correlation coefficient was 0.965,while the MQSSFE was significantly moderately correlated with the modified Down and Black instruments(r=0.61).We believed that MQSSFE was adequately appropriate,reliable,and valid for assessing the methodological quality for finite element studies used in computational orthopaedics.The instrument could facilitate quality assessment in the systematic reviews of finite element models and checklists for fidelity.展开更多
The influences of rocker shoes on foot biomechanics were controversial because the interaction between two design factors—rocker angle and apex location,was usually omitted.This study investigated the interaction ef...The influences of rocker shoes on foot biomechanics were controversial because the interaction between two design factors—rocker angle and apex location,was usually omitted.This study investigated the interaction effects of rocker angle and apex location on plantar foot pressure,metatarsophalangeal/ankle angle,and Achilles tendon force during walking.Ten participants performed walking trials under six rocker shoe conditions:2 rocker angles(mild and severe)×3 apex locations(distal,standard,and proximal),wherein the plantar foot pressure was measured and the movement data were processed by musculoskeletal modeling to report joint angle and Achilles tendon force.A two-way ANOVA repeated measures was used for statistics.Significant interaction effects were reported in examinations of forefoot pressure,midfoot pressure,and metatarsophalangeal dorsiflexion.The standard apex significantly reduced peak forefoot and midfoot pressures(p=0.008–0.034,Hedges'g=0.75–0.84),which was further decreased by a severe rocker angle(p=0.006,Hedges'g=0.51–0.81).Moving the apex proximally reduced Achilles tendon forces(p<0.001,Hedges'g=0.80)and facilitated both metatarsophalangeal dorsiflexion and ankle plantarflexion during push-off(p=0.003–0.006,Hedges'g=0.03–0.82).Rocker angle seemed to have fewer effects on ankle joint angle and Achilles tendon force.We concluded that apex location was likely the dominant design factor of the rocker sole in influencing foot biomechanics,yet its interactions with rocker angle should be considered.The configuration of the two features could be varied to possess different therapeutic merits and adapt to specific application purposes.展开更多
Meniscal attachments provide constraint for meniscus and contribute to knee stability. However, the influence of attachments placement on articular mechanical environment remains unclear. The present study aims to cha...Meniscal attachments provide constraint for meniscus and contribute to knee stability. However, the influence of attachments placement on articular mechanical environment remains unclear. The present study aims to characterize the stress deterioration caused by abnormal attachment locations. Different placement of medial meniscal attachments were analyzed with a three-dimensional (3D) finite element (FE) model of knee joint. The articular stress distribution under compressive loadings indicates that abnormal placement of medial meniscal attachments could cause stress deterioration in meniscus and tibia plateau, which may increase the risk of OA. The influence of PMMA relocation was more severe than that of AMMA. The anterior displacement of both AMMA and PMMA could decrease the tibial contact area and therefore weakening the meniscal function of loading transmission. The present study provides an insight into the biomechanical character of meniscal attachments and may help improving the meniscal transplantation in the future.展开更多
基金supported by General Research Funds granted by the Hong Kong Research Grant Council(#Poly U152065/17E)funding from the National Natural Science Foundation of China(#11732015)。
文摘Background:Segment coordination variability(CV)is a movement pattern associated with running-related injuries.It can also be adversely affected by a prolonged run.However,research on this topic is currently limited.The purpose of this study was to investigate the effects of a prolonged run on segment CV and vertical loading rates during a treadmill half marathon.Methods:Fifteen healthy runners ran a half marathon on an instrumental treadmill in a biomechanical laboratory.Synchronized kinematic and kinetic data were collected every 2 km(from 2 km until 20 km),and the data were processed by musculoskeletal modeling.Segment CVs were computed from the angle-angle plots of selected pelvis-thigh,thigh-shank,and shank-rearfoot couplings using a modified vector coding technique.The loading rate of vertical ground reaction force was also calculated.A one-way MANOVA with repeated measures was performed on each of the outcome variables to examine the main effect of running mileage.Results:Significant effects of running mileage were found on segment CVs(p≤0.010)but not on loading rate(p=0.881).Notably,during the early stance phase,the CV of pelvis frontal thigh frontal was significantly increased at 20 km compared with the CV at 8 km(g=0.59,p=0.022).The CV of shank transverse vs.rearfoot frontal decreased from 2 km to 8 km(g=0.30,p=0.020)but then significantly increased at both 18 km(g=0.05,p<0.001)and 20 km(g=0.36,p<0.001).Conclusion:At the early stance,runners maintained stable CVs on the sagittal plane,which could explain the unchanged loading rate throughout the half marathon.However,increased CVs on the frontal/transverse plane may be an early sign of fatigue and indicative of possible injury risk.Further studies are necessary for conclusive statements in this regard.
基金This work was supported by the Key R&D Program granted by the Ministry of Science and Technology of China(reference number:2018YFB1107000)the National Natural Science Foundation of China(reference numbers:11732015,11972315)+1 种基金the Project of Academic Leader of Health System(reference number:PWRd2019-05)the Project of Novel Interdisciplinary of Health System(reference number:PWXx2020-08)in Pudong New Area,Shanghai,China.
文摘The methodological quality of subject-specific finite element analysis papers depends on the rigor of the study design and detailed description of key elements,while assessment instruments are often confined to clinical trials or quasi-experiments.This study aims to present an instrument for methodological quality assessment of singlesubject finite element analysis used in computational orthopaedics(MQSSFE).Based upon existing instruments and relevant review papers,a pilot version was developed consisting of 37 items with 6 domains,including study design and presentation of findings,subject recruitment,model reconstruction and configuration,boundary and loading conditions(simulation),model verification and validation,and model assumption and validity.We interviewed four experts in the field to assess the face validity and refined the instrument.The instrument was tested for interrater reliability among two assessors on nine finite element study papers.Also,the criterion validity was evaluated by comparing the similarity of the MQSSFE and the modified Down and Black instrument.The intraclass correlation coefficient was 0.965,while the MQSSFE was significantly moderately correlated with the modified Down and Black instruments(r=0.61).We believed that MQSSFE was adequately appropriate,reliable,and valid for assessing the methodological quality for finite element studies used in computational orthopaedics.The instrument could facilitate quality assessment in the systematic reviews of finite element models and checklists for fidelity.
基金This work was supported by the National Natural Science Foundation of China[grant numbers 11732015,11972315]the Innovation and Technology Commission of Hong Kong[grant number ITS/262/18].
文摘The influences of rocker shoes on foot biomechanics were controversial because the interaction between two design factors—rocker angle and apex location,was usually omitted.This study investigated the interaction effects of rocker angle and apex location on plantar foot pressure,metatarsophalangeal/ankle angle,and Achilles tendon force during walking.Ten participants performed walking trials under six rocker shoe conditions:2 rocker angles(mild and severe)×3 apex locations(distal,standard,and proximal),wherein the plantar foot pressure was measured and the movement data were processed by musculoskeletal modeling to report joint angle and Achilles tendon force.A two-way ANOVA repeated measures was used for statistics.Significant interaction effects were reported in examinations of forefoot pressure,midfoot pressure,and metatarsophalangeal dorsiflexion.The standard apex significantly reduced peak forefoot and midfoot pressures(p=0.008–0.034,Hedges'g=0.75–0.84),which was further decreased by a severe rocker angle(p=0.006,Hedges'g=0.51–0.81).Moving the apex proximally reduced Achilles tendon forces(p<0.001,Hedges'g=0.80)and facilitated both metatarsophalangeal dorsiflexion and ankle plantarflexion during push-off(p=0.003–0.006,Hedges'g=0.03–0.82).Rocker angle seemed to have fewer effects on ankle joint angle and Achilles tendon force.We concluded that apex location was likely the dominant design factor of the rocker sole in influencing foot biomechanics,yet its interactions with rocker angle should be considered.The configuration of the two features could be varied to possess different therapeutic merits and adapt to specific application purposes.
基金National Natural Science Foundation of Chinagrant number:10925208,1120101001+1 种基金National Basic Research Program of Chinagrant number:2011CB710901
文摘Meniscal attachments provide constraint for meniscus and contribute to knee stability. However, the influence of attachments placement on articular mechanical environment remains unclear. The present study aims to characterize the stress deterioration caused by abnormal attachment locations. Different placement of medial meniscal attachments were analyzed with a three-dimensional (3D) finite element (FE) model of knee joint. The articular stress distribution under compressive loadings indicates that abnormal placement of medial meniscal attachments could cause stress deterioration in meniscus and tibia plateau, which may increase the risk of OA. The influence of PMMA relocation was more severe than that of AMMA. The anterior displacement of both AMMA and PMMA could decrease the tibial contact area and therefore weakening the meniscal function of loading transmission. The present study provides an insight into the biomechanical character of meniscal attachments and may help improving the meniscal transplantation in the future.