结论：矫形器的功能就是施加力，所以力学性能就是功能性能

矫形器通过对肢体施加力来实现目的——矫正畸形、限制异常活动、支持无力的肢体、或者引导运动方向。

所以它的力学性能不是附属指标，而是功能本身。 刚度不够，支持不了；刚度过大，限制正常活动并可能造成压迫；矫正力不足，达不到矫正效果；矫正力过大，造成疼痛和组织损伤。

这些都是可以测量的物理量，但实务中矫形器的力学性能评价往往依赖经验和主观判断，客观数据较少。

力学性能的维度

维度 含义
刚度 抵抗变形的能力
强度 承受载荷不破坏的能力
活动范围 允许的关节活动角度
矫正力 施加给肢体的矫正力大小
力的分布 力在接触面的分布情况
疲劳性能 反复受力后的性能保持
变形恢复 卸载后是否恢复原形

刚度与活动范围常常是矛盾的 ——刚度高则活动受限，活动范围大则支撑能力下降。矫形器的设计就是在这个矛盾中找平衡点，而平衡点由临床目标决定。

刚度的测量

刚度不是一个数字，需要说明测量条件：

测量方向。 不同方向的刚度不同。比如踝足矫形器在背屈、跖屈、内外翻方向的刚度各不相同，应当分别测。

测量位置。 施力点和固定点的位置。

加载范围。 刚度可能随变形量变化（非线性），应当给出曲线而不只是单点值。

加载速度。 某些材料的刚度与加载速度相关。

温度。 热塑性材料的刚度受温度影响明显，体温下的刚度可能与室温不同。

最后一条容易被忽略。 矫形器贴身穿戴，材料温度接近体温，而测试通常在室温下做。对温度敏感的材料，建议在接近使用温度的条件下测量。

矫正力的评价

矫正力的评价比刚度更贴近临床目标：

力的大小。 施加给肢体的力，可以通过压力测量或者力传感器获得。

力的方向。 矫正力的方向决定矫正效果。

力的分布。 集中的力会造成压迫，分散的力更安全。三点受力系统中，各点的压力分布要评价。

力随活动的变化。 肢体活动时矫正力如何变化。

力随时间的变化。 材料松弛、绑带滑移都会使矫正力下降。

最后一条在实际中影响很大。 刚穿上时矫正力合适，几小时后由于材料松弛和绑带滑移，矫正力可能明显下降，矫正效果随之下降。建议测量矫正力随时间的衰减。

疲劳与耐久

矫形器每天穿脱、使用中反复受力，疲劳是实际问题：

穿脱循环。 反复穿脱导致的变形和磨损。

使用中的受力循环。 行走等活动中的反复受力。

连接件的耐久。 铰链、搭扣、绑带的耐久。

材料的蠕变。 长期受力下的永久变形。热塑性材料的蠕变尤其需要关注。

清洁与出汗的影响。 汗液和清洁剂对材料的作用。

建议做耐久后的性能复测 ——重新测刚度和矫正力，看衰减幅度。这组数据是确定更换周期的依据，而矫形器的更换周期目前多数凭经验。

与临床目标的关系

力学性能的指标要与临床目标对应：

矫正目标。 需要多大的矫正力、施加多久、允许什么范围的活动。

支持目标。 需要承担多少载荷、在哪些方向提供支撑。

限制目标。 需要限制哪些方向的活动、限制到什么程度。

引导目标。 需要引导什么运动模式。

这些目标由临床决定，力学性能是实现手段。 所以产品资料中给出具体的力学参数（刚度值、活动范围、矫正力范围），比笼统说「提供良好支撑」对临床更有价值。

定制与批量产品的差异

定制产品。 每件不同，力学性能的一致性靠工艺控制。评价更多是针对个体的验证。

批量产品。 可以做型式试验，但要考虑不同尺码的性能差异——同一设计的大小号，刚度可能不同。

建议批量产品按尺码分组做力学测试，而不是只测一个尺码然后覆盖全系列。尺寸变化会改变结构的力学特性。

接触界面的评价

矫形器施加力，力必然通过接触面传递，所以界面的评价同样重要：

压力分布。 受力区域的压力是否均匀，有无集中点。

边缘处理。 边缘是压力集中的常见位置，处理不当会造成压痕甚至破损。

衬垫的作用。 衬垫分散压力，但也会降低矫正的精确性。厚度是一个权衡。

骨突部位的处理。 应当避让或加强缓冲。

长时间穿戴后的皮肤反应。 这是最终的验证。

建议对矫正力较大的产品做界面压力测量，特别是三点力系统中的支点位置。这些位置的压力如果过高，使用者会因不适而减少穿戴时间，矫正效果随之打折。

活动范围的测量

对于允许活动的矫形器，活动范围是明确的指标：

可动方向的范围。 各方向允许的角度。

限位的可靠性。 达到限位后的阻挡是否可靠。

范围的可调性。 是否可调、调节的精度和保持。

活动中的阻力。 在允许范围内活动时的阻力大小。

这几项的数据应当在产品资料中给出，因为临床处方需要据此选择。「可调节活动范围」这样的描述不足以支持选择，需要具体的角度范围和调节步距。

我们的做法

做矫形器力学性能测试时，我们会分方向测刚度并给出曲线，而不是只给一个数值。 因为矫形器在各方向的性能不同，单一数值表达不了。

对于热塑性材料的产品，我们建议在接近体温的条件下测量，因为实际穿戴时材料温度接近体温，室温下的数据可能偏高。

另外，矫正力随时间的衰减我们建议单独测量，这一项对应实际穿戴中的效果保持，而常规测试通常只看初始值。

如果你有矫形器产品需要做力学性能验证，想先理清测试方案，可以把产品结构和临床目标发过来一起讨论，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，案例见案例。

English version

Conclusion. An orthosis works by applying force to a limb, to correct deformity, restrict abnormal movement, support a weak limb or guide the direction of motion. Its mechanical performance is therefore not a secondary characteristic but the function itself. Too little stiffness and it does not support; too much and it restricts normal movement and may compress. Too little corrective force and correction is not achieved; too much and pain and tissue damage follow. All of these are measurable physical quantities, yet in practice mechanical assessment of orthoses relies heavily on experience and subjective judgement, with little objective data.

Dimensions of mechanical performance. Stiffness is resistance to deformation. Strength is the capacity to carry load without failure. Range of movement is the joint motion permitted. Corrective force is the magnitude applied to the limb. Force distribution is how that force spreads across the contact area. Fatigue performance is retention after repeated loading. And recovery is whether the original shape returns after unloading. Stiffness and range of movement are frequently in conflict: high stiffness restricts motion, while a large range reduces support. Orthotic design seeks a balance within that conflict, and the balance point is determined by the clinical objective.

Measuring stiffness. Stiffness is not a single number and requires stated conditions. Direction matters, since stiffness differs by direction: an ankle-foot orthosis differs in dorsiflexion, plantarflexion and inversion-eversion, and each should be measured. Location matters, meaning where force is applied and where the device is fixed. Loading range matters, since stiffness may vary with deformation in a non-linear way, so a curve should be given rather than a single point. Loading rate matters for materials whose stiffness is rate-dependent. And temperature matters, since thermoplastic stiffness is markedly temperature-dependent and stiffness at body temperature may differ from that at room temperature. The last is easily overlooked: an orthosis is worn against the body and its material approaches body temperature, while testing is usually at room temperature. For temperature-sensitive materials, measure near the temperature of use.

Assessing corrective force. This sits closer to the clinical objective than stiffness. Magnitude, the force applied to the limb, can be obtained by pressure mapping or force transducers. Direction determines the corrective effect. Distribution matters because concentrated force compresses while distributed force is safer, and in a three-point force system the pressure at each point should be assessed. Variation with movement examines how corrective force changes as the limb moves. And variation with time examines decline, since material relaxation and strap slippage both reduce corrective force. The last has substantial practical effect: force may be appropriate when first fitted and noticeably lower after a few hours as the material relaxes and straps slip, with correction declining accordingly. Measure the decay of corrective force over time.

Fatigue and durability. Orthoses are donned and doffed daily and loaded repeatedly in use, making fatigue a real issue. Donning cycles cause deformation and wear. Loading cycles during walking and other activity accumulate. Connecting components including hinges, buckles and straps must endure. Material creep produces permanent deformation under sustained load, a particular concern for thermoplastics. And perspiration and cleaning agents act on materials over time. Re-measure performance after durability testing, repeating stiffness and corrective force measurements to quantify decline. That data provides a basis for replacement intervals, which are currently set mostly by experience.

Relationship to clinical objectives. Mechanical parameters must correspond to clinical aims. A corrective aim specifies how much force, applied for how long, with what range of movement permitted. A support aim specifies how much load is carried and in which directions. A restriction aim specifies which directions are limited and to what extent. And a guidance aim specifies which movement pattern is to be guided. These aims come from the clinic and mechanical performance is the means. Stating specific mechanical parameters in product documentation, such as stiffness values, ranges of movement and corrective force ranges, is therefore far more clinically useful than a general claim of good support.

Custom versus series products. Custom products differ unit by unit, with consistency achieved through process control, and assessment is largely individual verification. Series products can undergo type testing, but performance differences between sizes must be considered, since the same design in different sizes may differ in stiffness. Test series products by size group rather than testing one size and extrapolating across the range, because dimensional change alters structural mechanical characteristics.

How we handle it. For orthotic mechanical testing we measure stiffness by direction and present curves rather than single values, because performance differs by direction and one number cannot express it. For thermoplastic products we suggest measuring near body temperature, since the material in wear is close to body temperature and room-temperature data may read high. We also suggest measuring the decay of corrective force over time as a separate item, since it corresponds to retention of effect during wear while routine testing examines only initial values.

Send us the construction and clinical objectives and we will work out the test approach. Phone or WeChat: +86 132 4819 8029.