A New Biomechanical Model to Examine Joint Control Adaptations during Running in

描述（由申请人提供）：在美国有超过160万人患有肢体丧失，仅在美国每年就有8万至9万例下肢截肢手术。运动减轻了我们在家庭、工作和社区中进行日常活动的能力，对于下肢截肢的个体来说，达到运动水平以最大限度地提高生活质量是必要的。早期对下肢截肢者（ILEA）“功能能力”的研究发现，最困难的体育活动是跑步。跑步专用假体（RSPs）的最新发展吸引了许多ILEA选择跑步作为他们的心血管运动形式，并且之前研究中报道的跑步对心血管的益处很可能延伸到这一人群。然而，正如我们的初步数据和先前的研究所表明的那样，使用RSP跑步的冲击力和机械适应性可能会使这一群体面临身体损伤和退行性关节疾病的风险。我们对ILEA运行的初步数据表明，记录的地面反作用力对肢肢提供了不对称载荷，其中完整肢肢承受的载荷大于残肢。这种模式在不同的跑步速度下是一致的。不对称肢体负荷已被认为是退行性关节疾病（DJD）发生和发展的危险因素，但需要更具体的数据，如关节动力学的适应，来更好地理解DJD和过度使用损伤的机制。不幸的是，非常有限的研究提供了更具体的关节加载机制和ILEA在跑步过程中的适应性。此外，目前还没有有效的生物力学模型来分析与rsp一起跑步的ILEA关节动力学。我们的初步工作已经建立了这样一个模型，并表明准确的关节动力学测量可以估计和解释。使用该模型，我们建议评估通过下肢的力传递和与rsp一起运行的ILEA的生物力学适应性。通过系统地测试一系列跑步速度，我们将检查达到这些速度所采用的关节动力学适应，并将ILEA适应与身体健全的对照组进行比较和对比。我们的中心假设是，通过关节动力学适应测量，与健全的跑步者相比，使用RSP跑步会对ILEA的完整肢体造成更大的压力。本研究项目的长期目标是描述ILEA跑步的特征，并将这些发现作为制定rsp和康复策略的科学基础，以最大限度地减少过度使用损伤的可能性，同时最大限度地提高ILEA的健康和生活质量。

DESCRIPTION (provided by applicant): Over 1.6 million people live with limb loss in the United States, and 80,000 to 90,000 lower limb amputation surgeries are performed each year in this country alone. Locomotion eases our ability to perform our everyday activities at home, work, and in the community, and it is imperative for individuals who undergo lower extremity amputations to achieve locomotive levels to maximize quality of life. Early studies on "functional capabilities" of individuals with lower extremity amputations (ILEA) found that the most difficult physical activity was running. Recent developments of running-specific prostheses (RSPs) have attracted many ILEA to choose running as their form of cardiovascular exercise and it is likely that the cardiovascular benefits of running reported in prior studies extend to this population. However, the impact forces and mechanical adaptations of running with an RSP may put this group at risk for physical injuries and degenerative joint diseases, as suggested by our preliminary data and previous studies. Our preliminary data on ILEA running show that the ground reaction forces recorded provide asymmetrical loading to the limbs with the intact limb bearing a greater load than the residual limb. This pattern was consistent at different running velocities. Asymmetrical limb loading has been indicated as a risk factor in the development and progression of degenerative joint diseases (DJD), but more specific data, such as adaptations in joint kinetics, are needed to better understand the mechanisms of DJD and overuse injuries. Unfortunately, a very limited number of studies provide insights into more specific mechanisms of joint loading and adaptations made by ILEA during running. Furthermore, no validated biomechanical models currently exist for joint kinetic analyses of ILEA running with RSPs. Our preliminary work has developed such a model and indicates that accurate joint kinetic measurements can be estimated and interpreted. Using this model we propose to assess the force transmission through the lower extremities and the biomechanical adaptations of ILEA running with RSPs. By systematically testing a range of running velocities, we will examine joint kinetic adaptations employed to achieve these velocities to compare and contrast ILEA adaptations to those of able-bodied control subjects. Our central hypothesis is that running with an RSP will cause greater strain on the intact limb of ILEA compared to able-bodied runners as measured by joint kinetic adaptations. The long-term objective of this research program is to characterize ILEA running and use these findings as a scientific foundation to develop RSPs and rehabilitation strategies that minimize the potential for overuse injury while maximizing the health and quality of life for ILEA. PUBLIC HEALTH RELEVANCE: The recent developments in running-specific prostheses (RSPs) have attracted many individuals with low- extremity amputations (ILEA) to running for cardiovascular exercise, and it is likely that the cardiovascular benefits of running reported in previous studies can generalize to ILEA. However, the impact forces and mechanical adaptations of running with an RSP may put this group at risk for physical injuries and degenerative joint diseases. We propose to assess these risks by measuring the force transmission through the lower extremities and biomechanical adaptations of ILEA running with RSPs using biomechanical models developed and validated in our preliminary studies.