Beam Theory and Finite Element Approaches to Modelling the Stresses in the Second Metatarsal During Running

拟进行的博士项目将研究跑鞋、足部打击方式和步频对跑步时体内第二跖骨劳损的影响。该项目将采用多学科方法，整合生物力学和工程程序，使用非侵入性技术开发第二跖骨的动态3D模型。跖骨应变与应力性骨折的发展有关，已知在负重体力活动期间应变会增加。跖骨应力性骨折是运动员和军人的一种严重损伤，第二跖骨是最常见的骨折骨之一。由于诊断所需的昂贵的磁共振成像程序和漫长的恢复时间，这种损伤与相当大的经济成本有关。由于评估骨应变的困难，目前尚不清楚鞋类、足部打击方式和跑步节奏等变量对跖骨应变的影响。因此，目前尚不清楚哪些因素可以有效地控制以减少跑步时跖骨的劳损。该项目的目的有三个方面：1)使用有限元分析技术开发第二跖骨的3D模型，以便在运行过程中估计轴向和弯曲应变。2)评估鞋类、足部打击方式、跑步节奏等可变变量对跖骨劳损的影响。3)确定在跑步过程中，哪种鞋、脚击和跑步节奏的组合能使跖骨劳损降到最低。为了实现这些目标，将在跑步过程中收集生物力学数据，并获得足部的磁共振图像。利用这些信息将创建第二跖骨的3D模型，并通过有限元分析确定跑步时骨骼的应力和应变。生物力学数据将在跑步试验中收集，在跑步试验中，鞋子、脚的击打模式和跑步节奏被操纵。

The proposed doctoral project will investigate the influence of footwear, foot strike pattern and stride cadence on in vivo second metatarsal strain during running. This project will use a multidisciplinary approach, integrating biomechanical and engineering procedures to develop a dynamic 3D model of the second metatarsal, using non-invasive techniques.Metatarsal strain is associated with stress fracture development, with strain known to increase during weight-bearing physical activity. Metatarsal stress fractures are a burdensome injury in both athletic and military populations, with the second metatarsal being one of the most commonly fractured bones. This injury is associated with considerable financial cost as a result of the expensive magnetic resonance imaging procedures required for diagnosis, and the lengthy recovery time. Due to the difficulties in assessing bone strain, it is presently unclear what influence variables such as footwear, foot strike pattern and running cadence have on metatarsal strain. Therefore it remains unknown which factors can be manipulated effectively to reduce strain in the metatarsals during running.The aim of this project is threefold:1) To develop a 3D model of the second metatarsal using finite element analysis techniques, allowing estimates of axial and bending strain during running.2) To assess the influence of modifiable variables, including footwear, foot strike pattern, and running cadence on metatarsal strain.3)To identify which combination(s) of footwear, foot strike and running cadence results in the lowest metatarsal strain during running.In order to achieve these aims, biomechanical data will be collected during running, and magnetic resonance images of the foot will be obtained. A 3D model of the second metatarsal will be created using this information, and finite element analyses will determine stress and strain along the bone during running. Biomechanical data will then be collected during running trials in which footwear, foot strike pattern and running cadence have been manipulated.