Computational Strategies for Balancing Trade-offs between Risk and Effort during Walking

了解导致跌倒风险的因素对于改善几个神经运动障碍人群的健康和生活质量具有广泛的意义，这些人群包括中风后患者、帕金森氏症患者和截肢者。与跌倒相关的医疗成本也很高：仅在美国，65岁以上的人跌倒的成本就约为500亿美元。减少跌倒风险的传统方法侧重于增强体力或培训人们制定更有效的策略，以从失去平衡的状态中恢复过来。然而，这些方法未能解决人们所做选择的作用。例如，人们摔倒可能是因为他们难以准确判断风险，高估了自己的功能能力，或者倾向于风险承受能力。开发评估步行过程中风险认知和风险偏好的个体差异的方法，可能会导致一类新的减少跌倒的干预措施，从而提高个人识别和避免将其推高至体力承受能力之外的潜在风险的能力。目前关于人类如何选择步行模式特征的理论模型主要是为了在风险中性的情况下将与能源相关的成本降至最低。目前工作的总体目标是将当前的风险中性理论扩展到更普遍的、临床上相关的运动风险敏感理论。研究人员将使用一种新的方法来研究人们在使用风险敏感的决策框架过程中如何平衡努力和风险之间的权衡。他们还将确定其他领域基于风险和努力的决策模型是否解释了人们如何在与不同水平的身体风险和努力相关的路线之间做出选择的年龄差异。除了确定步行过程中行为选择的基本原则外，这项工作还将为高中生提供在实验运动控制、生物力学和游戏开发的交叉点工作的实践经验。研究人员将与洛杉矶当地的一所高中合作，开发基于项目的活动，重点是符合共同核心和下一代科学标准的统计思维和生物力学。这些活动将通过南加州大学维特比K-12干细胞中心、首席调查员网站和Github提供给公众使用。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding factors that contribute to fall risk has broad implications for improving the health and quality of life for several populations with neuromotor impairments, including people post-stroke, people with Parkinson’s disease, and amputees. There are also significant medical costs associated with falls: In the United States alone, falls among people who are at least 65-years old incur costs of approximately $50 billion. Conventional approaches to reducing the risk of falling focus on building strength or training people in more effective strategies to recover from loss of balance. However, these approaches fail to address the role of the choices that people make. For example, people may fall because they have difficulty judging risk accurately, overestimate their functional capacity, or tend to be risk tolerant. Developing methods to assess individual differences in risk perception and risk preference during walking could lead to a new class of fall-reducing interventions that improve a person’s ability to identify and avoid potential risks that push them beyond their physical capacity. Current theoretical models of how humans select features of their walking pattern primarily aim to minimize an energy-related cost in a risk-neutral context. The overall objective of the present work is to extend the current risk-neutral theory to a more generalizable, and clinically relevant, risk-sensitive theory of locomotion. The investigators will use a novel approach to examine how people balance trade-offs between effort and risk during walking through the use of a risk-sensitive decision-making framework. They will also determine if models of risk- and effort-based decision-making in other domains explain age-dependent differences in how people choose between routes associated with varying levels of physical risk and effort. In addition to identifying fundamental principles of behavior selection during walking, the work will also provide high school students with practical experiences working at the intersection of experimental motor control, biomechanics, and game development. The investigators will collaborate with a local high school in Los Angeles to develop project-based activities focused on statistical thinking and biomechanics that align with the Common Core and Next Generation Science Standards. These activities will be made available for the public to use through the USC Viterbi K-12 Stem Center, on the principal investigator’s website, and via Github.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.