A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments an...A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments and finite element analysis to investigate the midfoot biomechanics.A foot-ankle finite element model simulating the mid-stance phase of the normal gait was developed and the model validated in in vitro experimental tests.Experiments used seven in vitro samples of fresh human cadavers.The simulation found that the first principal stress peaks of all midfoot bones occurred at the navicular bone and that the tensile force of the spring ligament was greater than that of any other ligament.The experiments showed that the longitudinal strain acting on the medial cuneiform bone was-26.2±10.8μ-strain,and the navicular strain was-240.0±169.1μ-strain along the longitudinal direction and 65.1±25.8μ-strain along the transverse direction.The anatomical position and the spring ligament both result in higher shear stress in the navicular bone.The load from the ankle joint to five branches of the forefoot is redistributed among the cuneiforms and cuboid bones.Further studies on the mechanism of loading redistribution will be helpful in understanding the biomechanics of the entire foot.展开更多
Although midfoot injury,especilly Lisfranc sprain,is a relative rare traumatic pathology,if overlooked or treated incorrectly,the damage will develop into chronic Lisfranc injury,which is characterized by lifelong res...Although midfoot injury,especilly Lisfranc sprain,is a relative rare traumatic pathology,if overlooked or treated incorrectly,the damage will develop into chronic Lisfranc injury,which is characterized by lifelong residual symptoms.The differences in injury severity,healing rates,treatment plans,and patient adherence make pro-spective investigations of the pathogenesis of Lisfranc injury very dificult to conduct.The development of ananimal model that mimics the symptoms of humans with chronic Lisfranc injury has the potential to lessen thechallenges associated with prospective human research.Previous research has successfully used a mouse model to explore the biomechanics of the human ankle joint.However,it remains to be determined if the mouse model canmimic human midfoot functions based on their similarities in anatomical structure.In this study,the anatomicalstructure of the mouse and human midfoot were compared by CT scan.The animal image data were obtainedfrom 10 male C57BL/6J mice(20 feet)by micro-CT.The human data were obtained from six volunteers(six feet)by CT scanning.The three-dimensional skeletal structure of the midfoot was reconstr ucted,and the morphologicalparameters were measured by a plane projection method.There were no significant differences among thehindfoot adductus angle(mice:28.86±6.27°;human:25.45±2.70°),metatarsus aductus angle(mice:11.34±2.95°;human:11.48±3.97°),or the transverse arch angle(mice:111.77±4.70°;human:111.84±6.34°)between the mice and humans.The mice had a comparable Lisfranc joint complex architecture compared tohumans in both coronal and transverse planes.The lateral cuneiform was fused with the navicular bone in mice,which would provide better intrinsic stability than in humans.Future research is necessary to evaluate the mouse midfoot injury model and the similarities of their neuro-musculo-skletal systems with humans.展开更多
Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it ...Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it has been recommended that runners who use a rearfoot strike would benefit by changing their footstrike although there is little scientific evidence for suggesting such a change. The rearfoot strike is clearly more prevalent. The major reasons often given for changing to a mid-or forefoot strike are(1) it is more economical;(2) there is a reduction in the impact peak and loading rate of the vertical component of the ground reaction force; and(3) there is a reduction in the risk of a running-related injuries. In this paper,we critique these 3 suggestions and provide alternate explanations that may provide contradictory evidence for altering one's footstrike pattern.We have concluded, based on examining the research literature, that changing to a mid-or forefoot strike does not improve running economy, does not eliminate an impact at the foot-ground contact, and does not reduce the risk of running-related injuries.展开更多
基金supported by the National Natural Science Foundation of China(11302154,11272273)China Postdoctoral Science Foundation(2013M530211)+1 种基金Opening Project of Shanghai Key Laboratory of Orthopaedic Implants(KFKT2013002)Fundamental Research Funds for the Central Universities
文摘A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments and finite element analysis to investigate the midfoot biomechanics.A foot-ankle finite element model simulating the mid-stance phase of the normal gait was developed and the model validated in in vitro experimental tests.Experiments used seven in vitro samples of fresh human cadavers.The simulation found that the first principal stress peaks of all midfoot bones occurred at the navicular bone and that the tensile force of the spring ligament was greater than that of any other ligament.The experiments showed that the longitudinal strain acting on the medial cuneiform bone was-26.2±10.8μ-strain,and the navicular strain was-240.0±169.1μ-strain along the longitudinal direction and 65.1±25.8μ-strain along the transverse direction.The anatomical position and the spring ligament both result in higher shear stress in the navicular bone.The load from the ankle joint to five branches of the forefoot is redistributed among the cuneiforms and cuboid bones.Further studies on the mechanism of loading redistribution will be helpful in understanding the biomechanics of the entire foot.
基金This work was supported by the National Key R&D Program of China(No.2018YFB1107000)the National Natural Science Foundation of China(11572211).
文摘Although midfoot injury,especilly Lisfranc sprain,is a relative rare traumatic pathology,if overlooked or treated incorrectly,the damage will develop into chronic Lisfranc injury,which is characterized by lifelong residual symptoms.The differences in injury severity,healing rates,treatment plans,and patient adherence make pro-spective investigations of the pathogenesis of Lisfranc injury very dificult to conduct.The development of ananimal model that mimics the symptoms of humans with chronic Lisfranc injury has the potential to lessen thechallenges associated with prospective human research.Previous research has successfully used a mouse model to explore the biomechanics of the human ankle joint.However,it remains to be determined if the mouse model canmimic human midfoot functions based on their similarities in anatomical structure.In this study,the anatomicalstructure of the mouse and human midfoot were compared by CT scan.The animal image data were obtainedfrom 10 male C57BL/6J mice(20 feet)by micro-CT.The human data were obtained from six volunteers(six feet)by CT scanning.The three-dimensional skeletal structure of the midfoot was reconstr ucted,and the morphologicalparameters were measured by a plane projection method.There were no significant differences among thehindfoot adductus angle(mice:28.86±6.27°;human:25.45±2.70°),metatarsus aductus angle(mice:11.34±2.95°;human:11.48±3.97°),or the transverse arch angle(mice:111.77±4.70°;human:111.84±6.34°)between the mice and humans.The mice had a comparable Lisfranc joint complex architecture compared tohumans in both coronal and transverse planes.The lateral cuneiform was fused with the navicular bone in mice,which would provide better intrinsic stability than in humans.Future research is necessary to evaluate the mouse midfoot injury model and the similarities of their neuro-musculo-skletal systems with humans.
文摘Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it has been recommended that runners who use a rearfoot strike would benefit by changing their footstrike although there is little scientific evidence for suggesting such a change. The rearfoot strike is clearly more prevalent. The major reasons often given for changing to a mid-or forefoot strike are(1) it is more economical;(2) there is a reduction in the impact peak and loading rate of the vertical component of the ground reaction force; and(3) there is a reduction in the risk of a running-related injuries. In this paper,we critique these 3 suggestions and provide alternate explanations that may provide contradictory evidence for altering one's footstrike pattern.We have concluded, based on examining the research literature, that changing to a mid-or forefoot strike does not improve running economy, does not eliminate an impact at the foot-ground contact, and does not reduce the risk of running-related injuries.
