Assessing the impact of hydrodynamic loads on shoulder joint injuries in swimming

在英国政府的产业战略中，医疗保健被确定为需要进一步研究和创新的六个关键领域之一。提高普通人群的活动和健康水平是应对与肥胖和人口老龄化有关的健康挑战的关键。游泳被认为是有益的，因为它提供了一种广泛适用于普通公众的非负重、全身的心血管运动形式。然而，对健康和健身的好处可能会被肩伤风险的增加所抵消，肩伤是这项运动中常见的情况。上肢产生了很大比例的游泳推进力，这表明相应肌肉骨骼结构的机械负荷过重可能与受伤风险增加有关。然而，关于作用在手臂上的非定常水动力或上肢的机械载荷以及它们在导致游泳者受伤方面的作用，人们知之甚少。该项目旨在确定作用在游泳运动员手臂上的流体力，并通过了解这种载荷在肩关节周围的肌肉骨骼结构之间的分配来阐明肩部损伤的机制。在已知肌肉骨骼解剖学、运动学和外力的情况下，计算模型允许量化内部载荷条件。作用在游泳者身上的外部水动力由肢体几何形状和由划水路径定义的局部水流速度决定。这些不稳定的力无法测量，必须从计算机模拟中得出，并由详细的冲程运动学和局部手臂几何形状提供信息。浸没边界CFD方法将被用来复制使用新的Quanalys水下运动捕获系统获得的高保真行程运动学。手臂的表面扫描将提供局部几何形状，软组织变形将通过在手臂上应用标记簇(Warner和Heller，2016)和最佳通用形状技术(OCST)(Taylor等人，2005年)进行评估。这将与从水下数字图像相关(DIC)获得的全场变形进行比较。软组织的变形依赖于肌肉的激活和外力的作用，在游泳过程中会引起身体形态的变化，从而影响运动过程中形成的流动特征和压力分布。该项目将开发捕捉这些内力和外力之间复杂相互作用的方法，这是更广泛地估计游泳动物局部组织力学的关键一步。这些定量的知识将为未来的治疗和预防措施提供依据，以减少肩部疼痛和伤害。该项目的更广泛影响将是开发可应用于生物或变形结构的高保真测量技术。这与工业战略中的其他重点领域密切一致，如机器人和人工智能，在这些领域，软机器人正变得越来越受欢迎，并强调需要“为英国工业提供世界领先的测量科学和技术”。

Healthcare was identified as one of six key areas requiring additional research and innovation in the UK government's Industrial Strategy. Increasing activity and fitness levels across the general population is key to combatting the health challenges associated with obesity and an ageing population. Swimming is considered to be beneficial as it offers a non weight-bearing, full-body form of cardiovascular exercise widely available to the general public. Benefits to health and fitness might be offset, however, by an increased risk of shoulder injury, a common occurrence within the sport. The upper limbs produce a large proportion of the propulsive forces for swimming, suggesting that mechanical overload of the respective musculoskeletal structures might be related to the increased injury risk. However, little is known about the unsteady hydrodynamic forces acting on the arm or the mechanical loads in the upper limbs and their role in predisposing a swimmer to injury. This project aims to determine the fluid forces acting on a swimmer's arm and elucidate mechanisms of shoulder injury by understanding how this load is shared between the musculoskeletal structures around the shoulder joint.Computational models allow the internal loading conditions to be quantified provided that the musculoskeletal anatomy, kinematics and external forces are known. The external, hydrodynamic forces acting on a swimmer are governed by the limb geometry and the local flow velocity defined by the stroke path. These unsteady forces cannot be measured and have to be derived from computer simulations, informed by detailed stroke kinematics and the local arm geometry. An immersed boundary CFD method will be used to replicate high fidelity stroke kinematics obtained using the new Qualysis underwater motion capture system. Surface scans of the arm will provide the local geometry and soft tissue deformations will be assessed through the application of marker clusters to the arm (Warner and Heller, 2016) and the Optimal Common Shape Technique (OCST) (Taylor et al., 2005). This will be compared to full field deformations obtained from underwater Digital Image Correlation (DIC). Soft tissue deformations depend on the muscle activation and the external forces, causing changes to the body shape during swimming which impact on the developed flow features and pressure distribution. The project will develop methods for capturing these complex interactions between internal and external forces, a critical step for estimating the local tissue mechanics in swimming animals more generally. Such quantitative knowledge will inform future treatments and preventative measures to reduce shoulder pain and injuries.A wider impact of this project will be the development of high fidelity measurement techniques that can be applied to biological or deforming structures. This aligns closely with other focus areas in the Industrial strategy such as robotics and artificial intelligence, where soft robotics are becoming more popular, and the highlighted need to 'provide UK industry with world-leading measurement science and technology'.