结论：接受腔决定假肢好不好用，而不是脚板或膝关节

假肢由接受腔、连接件、功能部件（膝关节、踝足）组成。其中接受腔是与人体连接的界面，它的适配质量直接决定假肢能不能用、用得舒不舒服。

实际情况是：功能部件再先进，接受腔不合适，假肢的实际使用价值也有限。 使用者可能因为疼痛、磨损、不稳定而减少使用甚至放弃。

所以接受腔的评价是假肢工作中分量很重的部分，但它的评价方法相对不标准化，多数依赖经验判断。引入客观测量可以提高评价的可靠性。

适配的评价维度

维度 评价内容
压力分布 各部位的界面压力与承重分配
悬吊 假肢与残肢的连接可靠性
对线 接受腔与功能部件的空间关系
活动范围 是否限制关节活动
皮肤状况 使用后的皮肤反应
稳定性 行走中残肢在腔内的相对运动
舒适度 主观感受

压力分布是可以客观测量的维度，其他维度也有测量方法，但压力分布最直接对应组织安全。

压力分布的测量

原理与坐垫的压力测量类似，但接受腔的情况更复杂：接触面是三维曲面；压力分布随步态周期变化；以及传感器在腔内会影响适配本身。

测量时要注意：

传感器的厚度影响。 腔内空间紧凑，传感器会改变适配状态。应当用薄型传感器并说明这个影响。

动态测量。 静态站立的分布与行走中的分布差别很大，评价应当包含动态数据。

关键部位的覆盖。 承重区、敏感区（骨突、神经走行处）要覆盖到。

步态周期的对应。 压力峰值出现在步态的哪个阶段，对分析原因有帮助。

对侧对比。 与健侧的对比可以提供参考。

「敏感区的压力」是评价的重点。 骨性突起和神经走行处的压力应当被控制，而承重区应当承担主要载荷。分布反了，就是适配不当。

材料与工艺的影响

内衬材料。 硅胶、聚氨酯等材料的力学特性不同，影响压力分布和舒适度。

腔体材料与厚度。 影响刚度，刚度影响载荷传递。

制作工艺。 取型、修型、成型的每一步都影响最终形状。

表面处理。 内表面的光洁度影响摩擦和皮肤状况。

接口件。 与功能部件的连接方式影响力的传递路径。

材料的长期变化也要考虑 ——内衬材料会老化、压缩变形，腔体材料可能变形。这些变化会改变适配状态。

随时间变化的问题

接受腔适配是动态的，会随时间变化，原因有几方面：

残肢容积变化。 术后残肢会持续变化，早期变化较快。日内也有波动（活动、体液分布）。

体重变化。 使用者体重变化直接影响残肢容积。

材料变化。 内衬压缩、腔体变形。

使用习惯变化。 活动量和方式改变导致受力模式改变。

所以接受腔需要定期复查和调整，而不是配好一次就一直用。资料和使用指导中应当说明这一点，并给出复查的建议频次和判断依据。

日内容积波动的应对包括袜套的增减、可调结构等。这些方式的有效性也可以通过压力测量来评价。

评价的实施

静态评价。 站立位的压力分布、对线检查、外观检查。

动态评价。 行走中的压力变化、步态观察、悬吊效果。

使用后评价。 穿戴一段时间后的皮肤检查、使用者反馈。

长期随访。 定期复查适配状态。

建议把主观评价与客观测量结合 ——使用者的感受是重要信息，但感受可能滞后于组织损伤（特别是感觉减退的使用者），客观测量可以提前发现问题。

数据的价值

压力测量数据在几个方面有用：

指导修改。 哪里压力过高就修哪里，比凭经验试错效率高。

评价修改效果。 修改前后对比，确认改善。

积累经验。 数据积累之后，可以总结出针对不同残肢形态的适配规律。

沟通工具。 用图示与使用者沟通，比口头描述清楚。

争议的依据。 出现问题时，数据是客观依据。

悬吊方式的评价

悬吊决定假肢与残肢的连接可靠性，常见方式各有特点：

吸着式。 依靠负压悬吊，密封性是关键。密封失效会导致悬吊失效。

锁具式。 通过销栓与锁具连接，可靠但远端可能受牵拉。

带式与背带式。 简单可靠，但舒适度和外观有代价。

楔形与解剖学悬吊。 利用骨性结构，无额外部件。

评价内容包括： 悬吊力的大小、行走中的活塞运动量（残肢在腔内的上下相对移动）、密封的保持能力（吸着式）、以及长时间使用后的变化。

「活塞运动量」是客观的评价指标 ——运动量大说明悬吊不足，会导致皮肤摩擦和能量损耗。这一项可以通过动态测量获得。

内衬材料的性能

内衬直接接触皮肤且承担缓冲，性能评价包括：

压缩性能与回弹。 影响压力分散。

压缩永久变形。 长期使用后是否变薄，变薄会改变适配。

摩擦特性。 与皮肤和与腔体内壁的摩擦，影响活塞运动和皮肤安全。

透气与透湿。 影响接触面的微气候，与皮肤问题直接相关。

耐清洁。 每日清洁对材料的影响。

生物相容性。 长时间皮肤接触，相关项目要考虑。

「压缩永久变形」是确定更换周期的依据，建议通过压缩循环试验测出衰减曲线。

我们的做法

做接受腔相关的评价时，我们建议同时做静态和动态的压力测量，因为行走中的压力峰值往往比静态站立高得多，而组织损伤多数发生在动态过程中。

对于材料方面的评价（内衬材料的压缩变形、老化），我们建议做耐久后的性能复测，得出衰减数据，据此给出内衬的更换周期建议。

如果你在做接受腔相关的评价或材料验证，想先理清测量方案，可以把产品或材料信息发过来一起讨论，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见手动轮椅检测与电动轮椅检测，标准信息见标准查询。

English version

Conclusion. A prosthesis comprises a socket, connecting components and functional components such as knee and ankle-foot units. The socket is the interface with the body, and how well it fits determines directly whether the prosthesis is usable and comfortable. In practice, however advanced the functional components, a poorly fitting socket limits the prosthesis's real value: the user may reduce wear or abandon it because of pain, abrasion or instability. Socket work therefore carries great weight in prosthetics, yet its assessment methods are comparatively unstandardised and rely largely on experienced judgement. Introducing objective measurement improves the reliability of that assessment.

Dimensions of fit. Pressure distribution covers interface pressure and load sharing at each region. Suspension covers the security of the connection between prosthesis and residual limb. Alignment covers the spatial relationship between socket and functional components. Range of movement covers whether joint motion is restricted. Skin condition covers the tissue response after wear. Stability covers relative movement of the limb within the socket during gait. And comfort covers subjective experience. Pressure distribution is the dimension most amenable to objective measurement, and while the others can also be measured, pressure corresponds most directly to tissue safety.

Measuring pressure distribution. The principle resembles cushion pressure mapping, but the socket case is more complex: the contact surface is a three-dimensional curve, distribution varies through the gait cycle, and a sensor inside the socket alters the fit it is measuring. Several points matter. Sensor thickness matters, since space inside a socket is tight and the sensor changes the fit, so thin sensors should be used and the effect noted. Dynamic measurement matters, since distribution during walking differs greatly from quiet standing and assessment should include dynamic data. Coverage of key regions matters, spanning load-bearing areas and sensitive ones over bony prominences and nerve paths. Correspondence with the gait cycle matters, since knowing at which phase peaks occur helps analysis. And comparison with the sound side can provide reference. Pressure over sensitive regions is the focus: it should be controlled while load-bearing regions carry the principal load, and a distribution that reverses this indicates poor fit.

Material and process effects. Liner material, whether silicone, polyurethane or another, has different mechanical characteristics affecting distribution and comfort. Socket material and thickness affect stiffness, which affects load transfer. Fabrication, through casting, rectification and forming, affects the final shape at every step. Surface finish inside the socket affects friction and skin condition. And the interface to functional components affects the load transfer path. Long-term material change must also be considered, since liner materials age and take a compression set and socket materials may distort, each altering the fit.

Changes over time. Socket fit is dynamic. Residual limb volume changes continuously after surgery, rapidly in the early period, and fluctuates within the day with activity and fluid distribution. Body weight changes affect limb volume directly. Materials change through liner compression and socket distortion. And habits change as activity level and type alter loading patterns. Sockets therefore need periodic review and adjustment rather than a single fitting, and documentation and user guidance should say so, with a recommended review frequency and criteria. Responses to daily volume fluctuation include adding or removing socks and adjustable constructions, and the effectiveness of these can also be evaluated through pressure measurement.

Conducting the assessment. Static assessment covers standing pressure distribution, alignment and visual inspection. Dynamic assessment covers pressure change during walking, gait observation and suspension effectiveness. Post-wear assessment covers skin inspection after a period of wear and user feedback. And long-term follow-up reviews fit periodically. Combine subjective assessment with objective measurement: the user's experience is important information, but it may lag tissue damage, particularly where sensation is reduced, and objective measurement can find problems earlier.

Value of the data. Pressure data guide modification, since relieving where pressure is high is more efficient than trial and error. They evaluate modifications, comparing before and after to confirm improvement. They build experience, since accumulated data reveal fitting patterns for different limb shapes. They serve as a communication tool, since an image explains more clearly than description. And they provide an objective basis where problems are disputed.

How we handle it. For socket assessment we suggest both static and dynamic pressure measurement, because peak pressures during walking are often far above those in quiet standing and tissue damage mostly occurs dynamically. For material assessment, covering liner compression set and ageing, we suggest performance re-measurement after durability testing to obtain decline data and set a liner replacement interval on that basis.

Send us the product or material information and we will work out the measurement approach. Phone or WeChat: +86 132 4819 8029.