Effect of prosthesis stiffness on impact force during in vivo step loads and gait

假体刚度对体内步态负载和步态冲击力的影响

• 批准号: 9030953
• 负责人: Steven A. Gard
• 金额: --
• 依托单位: JESSE BROWN VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-11-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9030953
• 关键词: Ankle; Attenuated; Beds; Biomechanics; Body Weight; Complex; Data; Environment; Financial compensation; Future; Gait; Health; Heel; Hip region structure; Impact evaluation; Investigation; Joints; Knee; Leg; Limb Prosthesis; Limb structure; Lower Extremity; Manufacturer Name; Measures; Mechanics; Mission; Monitor; Pain; Patient Care; Pelvis; Persons; Phase; Prosthesis; Prosthesis Design; Protocols documentation; Quality of life; Reaction; Reporting; Residual state; Shock; Side; Skin; System; Testing; Walking; absorption; attenuation; clinical practice; design; expectation; gait examination; improved; in vivo; indium arsenide; kinematics; limb amputation; novel; preference; prosthesis wearer; public health relevance; residual limb; response; soft tissue; walking speed; Ankle; Attenuated; Beds; Biomechanics; Body Weight; Complex; Data; Environment; Financial compensation; Future; Gait; Health; Heel; Hip region structure; Impact evaluation; Investigation; Joints; Knee; Leg; Limb Prosthesis; Limb structure; Lower Extremity; Manufacturer Name; Measures; Mechanics; Mission; Monitor; Pain; Patient Care; Pelvis; Persons; Phase; Prosthesis; Prosthesis Design; Protocols documentation; Quality of life; Reaction; Reporting; Residual state; Shock; Side; Skin; System; Testing; Walking; absorption; attenuation; clinical practice; design; expectation; gait examination; improved; in vivo; indium arsenide; kinematics; limb amputation; novel; preference; prosthesis wearer; public health relevance; residual limb; response; soft tissue; walking speed

Shock absorption is an inherent function of the able-bodied locomotor system. Able-bodied ambulators are not typically consciously aware of shock attenuation, but lower-limb prostheses users are often acutely aware of the jarring impact forces that can occur when they take a step with their prosthesis. These impact forces are transmitted through the prosthesis to the residual limb, making walking uncomfortable and even painful. Components with reduced stiffness are commonly prescribed in lower-limb prostheses to change the mechanical response of the prosthesis to an applied load, providing shock absorption and reducing forces transmitted to the residual limb during gait. However, contrary to expectations, these components do not generally decrease ground reaction force (GRF) loading peaks during gait, a commonly used indicator of shock absorption. Previous reports of increased subject preference for reduced-stiffness components indicate that these components are influencing the limb-prosthesis system. However, this influence has not been documented consistently in any biomechanical gait parameter. Currently, the difference in prosthetic stiffness required to overcome the passive contributions in total limb stiffness and enact a change in the impact force profiles is unknown. Therefore, it is important to evaluate the effect of changes in prosthetic stiffness in vivo and in a controlled impact environment. Furthermore, only manufacturer-recommended stiffness levels for any of these reduced-stiffness components have been previously evaluated. It is also important to determine if prosthesis users actively modulate total limb stiffness during walking in response to changes in prosthesis stiffness, preserving some minimum magnitude of impact force when reduced-stiffness components are incorporated into their prostheses. The purpose of this proposed study is to systematically vary the stiffness of a transtibial prosthesis and measure the force response during in vivo impact loading and gait. Impact forces will be measured as the prosthetic stiffness is systematically varied while using a novel in vivo impact-testing protocol that reduces the ability of the prosthesis user to influence impact forces. These data will then be compared with a quantitative gait analysis performed over the same prosthetic stiffness levels. This proposed study will be the first to perform a systematic evaluation of the impact force-prosthetic stiffness relationship. Reduced prosthetic stiffness is hypothesized to decrease impact force magnitudes during impact testing. GRF loading peaks are not expected to change between prosthetic stiffness conditions, indicating an active compensation strategy by the prosthesis user during gait. The proposed study is intended to lay the groundwork for a more complete understanding of how prosthetic components function in vivo. First, it would corroborate subjective data that indicates that reduced-stiffness components are capable of overcoming the low stiffness of the soft tissue of the residual limb and influencing the limb-prosthesis system, even in the absence of documented biomechanical changes during walking. Furthermore, the anticipated results would indicate that subjects are able to accommodate to changes in prosthetic component stiffness, requiring further investigations to identify, better understand, and develop components that can capitalize upon these adaptive mechanisms. Finally, these results would inform clinical practice and prosthetic design by indicating which levels of reduced prosthetic stiffness are effective at reducing impact forces within the residual limb and prosthesis as a whole.

休克吸收是能力强大的运动系统的固有功能。健全的救护物不是 通常有意识地意识到冲击衰减，但是下limb假体经常敏锐地意识到 当他们与假体迈出一步时，可能会发生刺耳的影响力。这些影响力是 通过假体传播到残留的肢体，使行走不舒服甚至痛苦。 较低的刚度降低的组件通常在下限假体中规定 假体对施加载荷的机械响应，提供减震和减少力 步态过程中传播到残留的肢体。但是，与期望相反，这些组成部分没有 通常会降低步态期间地面反作用力（GRF）载荷峰，这是一个常用的冲击指标 吸收。先前关于降低状态组件的主题偏爱增加的报道表明 这些组成部分正在影响肢体假定系统。但是，这种影响还没有 在任何生物力学步态参数中始终记录。目前，假肢僵硬的差异 要克服总肢体刚度的被动贡献并实施撞击力的变化所需 配置文件是未知的。因此，重要的是要评估体内假肢变化的影响 并在受控的影响环境中。此外，只有制造商推荐的刚度 以前已经评估过这些降低的状态成分。确定是否是否 假体使用者在行走过程中积极调节全肢僵硬，以应对假体的变化 刚度，当降低状态组件是 纳入他们的假肢。 这项拟议的研究的目的是系统地改变跨态假体和 测量体内撞击载荷和步态过程中的力响应。影响力将被衡量为 假体刚度在使用新颖的体内冲击测试方案时会系统地变化，从而减少了该协议 假体用户影响力的能力。然后将这些数据与定量进行比较 步态分析在相同的假肢刚度水平上执行。这项拟议的研究将是第一个 对影响力螺旋刚度关系进行系统评估。减少假肢 假设刚度可以降低冲击测试期间的影响力幅度。 GRF加载峰为 预计假肢僵硬条件之间不会改变，表明通过 步态期间的假体使用者。 拟议的研究旨在为对假肢的方式有更全面的理解奠定基础 组件在体内功能。首先，它将证实主观数据，表明降低状态 组件能够克服残留肢体软组织的低刚度并影响 即使在步行过程中没有有记录的生物力学变化的情况下，肢体预构系统也是如此。 此外，预期的结果将表明受试者能够适应变化 假体成分僵硬，需要进一步的研究以识别，更好地理解和发展 可以利用这些自适应机制的组件。最后，这些结果将为临床提供信息 练习和假肢设计通过指示哪些降低的假体刚度有效 减少残留肢体和整体假体内的影响力。