The anterior cruciate ligament plays a crucial role in maintaining stability within the knee joint,particularly for athletes who frequently experience its rupture.This study presents a novel approach using personalize...The anterior cruciate ligament plays a crucial role in maintaining stability within the knee joint,particularly for athletes who frequently experience its rupture.This study presents a novel approach using personalized three-dimensional(3D)parametric finite element modeling of the knee joint to simulate the treatment following anterior cruciate ligament reconstruction(ACLR)in both forward walking(FW)and drop landing(DL)tasks.The study encompasses two distinct cohorts:five healthy athletes and five ACLR patients.Biomechanical motion analysis was conducted on both cohorts,with the ACLR patient group evaluated at 6 and 9 months post-surgery.A comprehensive 3D parametric model of the knee joint was meticulously crafted.The findings reveal a notable reduction in stress on crucial knee structures such as the autograft,meniscus,and cartilages over time for both FW and DL tasks following ACLR,with a reduction in tissue tension of approximately 9.5%and 37%for FW and DL,respectively.This personalized model not only facilitates the investigation of knee joint tissue biomechanics post-ACLR but also aids in estimating the return-to-sports timeline for patients.By accommodating individual tissue geometries and incorporating patient-specific kinetic data,this model enhances our comprehension of post-ACLR biomechanics across various functional tasks,thereby optimizing rehabilitation strategies.展开更多
Different from sculling forward of water striders with their hairy water-repellent legs, water spiders walked very quickly on water surfaces. By using a shadow method, the walking of water spiders had been studied. Th...Different from sculling forward of water striders with their hairy water-repellent legs, water spiders walked very quickly on water surfaces. By using a shadow method, the walking of water spiders had been studied. The three-dimensional trajectories and the supporting forces of water spider legs during walking forward were achieved. Results showed that the leg movement could be divided into three phases： slap, stroke, and retrieve. Employing an effective strategy to improving walking efficiency, the sculling legs supported most of its body weight while other legs were lifted to reduce the lateral water resistance, which was similar to the strategy of water striders. These findings could help guiding the design of water walking robots with high efficiency.展开更多
Measuring walking forces of small or tiny insects can help the comprehension of their locomotion principles.However,as their size and force are generally too small,walking forces of small insects in sub-mg mass have n...Measuring walking forces of small or tiny insects can help the comprehension of their locomotion principles.However,as their size and force are generally too small,walking forces of small insects in sub-mg mass have never been actually measured.In this work,a convenient multi-lens and jelly surface based shadow method was developed for simultaneous multiple walking forces measuring,ranged from nN to mN with a sensitivity of sub-nN/pixel under ambient conditions.Walking force of six legs of a 0.3 mg water treader was demonstrated.The obtained results disclosed a rapid and extending middle leg strategy of water treader in walking forward above a jelly surface.This method is cost-effective and high-resolution,which could be easily used in measuring other tiny forces.展开更多
文摘The anterior cruciate ligament plays a crucial role in maintaining stability within the knee joint,particularly for athletes who frequently experience its rupture.This study presents a novel approach using personalized three-dimensional(3D)parametric finite element modeling of the knee joint to simulate the treatment following anterior cruciate ligament reconstruction(ACLR)in both forward walking(FW)and drop landing(DL)tasks.The study encompasses two distinct cohorts:five healthy athletes and five ACLR patients.Biomechanical motion analysis was conducted on both cohorts,with the ACLR patient group evaluated at 6 and 9 months post-surgery.A comprehensive 3D parametric model of the knee joint was meticulously crafted.The findings reveal a notable reduction in stress on crucial knee structures such as the autograft,meniscus,and cartilages over time for both FW and DL tasks following ACLR,with a reduction in tissue tension of approximately 9.5%and 37%for FW and DL,respectively.This personalized model not only facilitates the investigation of knee joint tissue biomechanics post-ACLR but also aids in estimating the return-to-sports timeline for patients.By accommodating individual tissue geometries and incorporating patient-specific kinetic data,this model enhances our comprehension of post-ACLR biomechanics across various functional tasks,thereby optimizing rehabilitation strategies.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51323006 and 51425502)the Tribology Science Fund of State Key Laboratory of Tribology(Grant No.SKLTKF17B18)
文摘Different from sculling forward of water striders with their hairy water-repellent legs, water spiders walked very quickly on water surfaces. By using a shadow method, the walking of water spiders had been studied. The three-dimensional trajectories and the supporting forces of water spider legs during walking forward were achieved. Results showed that the leg movement could be divided into three phases： slap, stroke, and retrieve. Employing an effective strategy to improving walking efficiency, the sculling legs supported most of its body weight while other legs were lifted to reduce the lateral water resistance, which was similar to the strategy of water striders. These findings could help guiding the design of water walking robots with high efficiency.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51323006 and 51425502)。
文摘Measuring walking forces of small or tiny insects can help the comprehension of their locomotion principles.However,as their size and force are generally too small,walking forces of small insects in sub-mg mass have never been actually measured.In this work,a convenient multi-lens and jelly surface based shadow method was developed for simultaneous multiple walking forces measuring,ranged from nN to mN with a sensitivity of sub-nN/pixel under ambient conditions.Walking force of six legs of a 0.3 mg water treader was demonstrated.The obtained results disclosed a rapid and extending middle leg strategy of water treader in walking forward above a jelly surface.This method is cost-effective and high-resolution,which could be easily used in measuring other tiny forces.
