Whole-Body Angular Momentum During Walking on Varied Surfaces in Individuals with

描述(申请人提供)：在美国，单侧经胫骨截肢(TTA)的患者数量正在迅速增长，这些患者患有各种步态缺陷，包括更大的风险和对摔倒的恐惧。跌倒是一个严重的健康问题，约占美国与伤害相关的医疗费用的30%。在倾斜的表面和楼梯上行走在日常生活活动中经常遇到，与在平地上行走相比，摔倒的风险更大，特别是对于残障人士，如截肢的人。近年来，人们研究了水平行走时全身角动量的变化，认为为了维持动态平衡，必须对全身角动量进行调节。分析额外的生物力学指标，如外部力矩和稳定裕度，当与全身角动量相结合时，可以得到一个全面的动态平衡观点。此外，电动假体最近已经商业化，并在降低步行的新陈代谢成本方面显示出良好的结果。然而，不同功能的假体在不同表面行走时对动态平衡的影响尚不清楚。这项拟议的工作旨在量化在TTA中使用被动和动力假体相对于非截肢者在楼梯和倾斜表面行走时的动态平衡。具体目标1：量化被动假体和非截肢者在楼梯上升和下降过程中全身角动量、外部力矩和稳定裕度的差异，以确定不同功能假体对跌倒风险的影响。具体目标2：量化被动假体TTA、动力假体和非截肢者在0度、5度和10度坡度倾斜和下坡行走时全身角动量、外部力矩和稳定裕度的差异，以确定不同功能假体对跌倒风险的影响。通过这些具体目标，更低的效果 测定截肢和假体功能变化对动态平衡的影响。角动量、外部力矩和稳定裕度的结果将通过关节动力学进一步解释，以确定可能有助于平衡控制的生物力学机制。这项拟议的工作为将这项研究实质上扩展到平衡控制、肌肉和假肢功能以及改变假肢控制策略的实验和计算研究提供了基础。此外，该方法还可以扩展到更多的患者群体。这项工作的长期目标是通过降低跌倒风险来提高下肢截肢患者的机动性、生产力和独立性。

DESCRIPTION (provided by applicant): The number of individuals with unilateral transtibial amputation (TTA) is rapidly growing in the United States, and these individuals suffer from a variety of gait deficits, including a greater risk and fear of falling. Falls are a serious health problem, and account for approximately 30% of injury-related medical costs in the U.S. Walking on sloped surfaces and on stairs is frequently encountered in daily living activities and presents a greater risk of falling relative to walking on level ground, particularly for people with disabilties, such as individuals with amputation. Recently, whole-body angular momentum has been investigated during level, unimpaired walking, and must be regulated in order to maintain dynamic balance. Analysis of additional biomechanical measures, such as the external moment and margin of stability, can result in a comprehensive view for dynamic balance when combined with whole-body angular momentum. In addition, powered prostheses have recently become commercially available, and have shown promising results in reducing the metabolic cost of walking. However, the effects of functionally different prostheses on dynamic balance during walking on varied surfaces remain unclear. The proposed work aims to quantify dynamic balance in TTA using both passive and powered prostheses relative to non-amputees during walking on stairs and on sloped surfaces. Specific Aim 1: Quantify differences in whole-body angular momentum, external moment and margin of stability between TTA using a passive prosthesis, using a powered prosthesis and non-amputees during stair ascent and descent to determine the effects of functionally different prostheses on fall risk Specific Aim 2: Quantify differences in whole-body angular momentum, external moment and margin of stability between TTA using a passive prosthesis, using a powered prosthesis and non-amputees during incline and decline walking on slopes of zero, five and ten degrees to determine the effects of functionally different prostheses on fall risk. Through these specific aims, the effects of a lower limb amputation and functional changes in the prosthesis on dynamic balance will be determined. The angular momentum, external moment and margin of stability results will be further interpreted using joint kinetics to identify biomechanical mechanisms that may contribute to balance control. The proposed work provides a foundation to substantially extend this research to experimental and computational studies of balance control, muscle and prosthesis function, and altered prosthesis control strategies. In addition, the approach can be extended to additional patient populations. The long-term objectives of this work are to improve mobility, productivity and independence in individuals with lower-limb amputation by reducing fall risk.