Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136, Bologna, Italy.
J Foot Ankle Res. 2022 May 19;15(1):38. doi: 10.1186/s13047-022-00547-2.
Ankle-Foot Orthoses (AFO) can be prescribed to allow drop-foot patients to restore a quasi-normal gait pattern. Standard off-the-shelf AFOs are cost-effective solutions to treat most patients with foot and ankle weakness, but these devices have several limitations, especially in terms of comfort. Therefore, custom AFOs are increasingly adopted to address drop-foot when standard solutions are not adequate. While the solid ones are the most common type of AFO, providing full stability and strong resistance to ankle plantarflexion, passive dynamic AFOs (PD-AFOs) represent the ideal solution for patients with less severe ankle weakness. PD-AFOs have a flexible calf shell, which can bend during the stance phase of walking and absorb energy that can be released to support the limb in the push-off phase. The aim of this review is to assess the state-of-the-art and identify the current limitations of PD-AFOs. An extensive literature review was performed in Google Scholar to identify all studies on custom PD-AFOs. Only those papers reporting on custom PD-AFOs were included in the review. Non peer-reviewed papers, abstract shorter than three pages, lecture notes and thesis dissertations were excluded from the analysis. Particular attention was given to the customization principles and the mechanical and functional tests. For each topic, the main results from all relevant papers are reported and summarized herein. There were 75 papers that corresponded to the search criteria. These were grouped according to the following macro-topics: 16 focusing on scanning technologies and geometry acquisition; 14 on customization criteria; 19 on production techniques; 16 on mechanical testing, and 33 on functional testing. According to the present review, design and production of custom PD-AFOs are becoming increasingly feasible due to advancements in 3D scanning techniques and additive manufacturing. In general, custom PD-AFOs were shown to provide better comfort and improved spatio-temporal parameters with respect to standard solutions. However, no customization principle to adapt PD-AFO stiffness to the patient's degree of ankle impairment or mechanical/functional demand has thus far been proposed.
踝足矫形器（AFO）可用于治疗垂足患者，使其恢复接近正常的步态模式。标准的现成 AFO 是治疗大多数足部和踝关节无力患者的具有成本效益的解决方案，但这些设备有几个局限性，尤其是在舒适度方面。因此，当标准解决方案不足时，越来越多地采用定制 AFO 来治疗垂足。虽然实心 AFO 是最常见的 AFO 类型，可提供完全的稳定性和对踝关节跖屈的强大阻力，但被动动态 AFO（PD-AFO）是踝关节无力程度较轻的患者的理想解决方案。PD-AFO 具有灵活的小腿壳，在步行的站立阶段可以弯曲，并吸收能量，在推进阶段可以释放这些能量来支撑肢体。本综述的目的是评估 PD-AFO 的最新技术并确定当前的局限性。在 Google Scholar 上进行了广泛的文献综述，以确定所有关于定制 PD-AFO 的研究。只有报告定制 PD-AFO 的论文才包括在综述中。非同行评审的论文、少于三页的摘要、讲义和学位论文被排除在分析之外。特别关注定制原则和机械及功能测试。对于每个主题，都从所有相关论文中报告并总结了主要结果。符合搜索标准的论文有 75 篇。这些论文根据以下宏观主题进行分组：16 篇聚焦于扫描技术和几何获取；14 篇关注定制标准；19 篇关注生产技术；16 篇关注机械测试，33 篇关注功能测试。根据本综述，由于 3D 扫描技术和增材制造的进步，定制 PD-AFO 的设计和生产变得越来越可行。一般来说，与标准解决方案相比，定制 PD-AFO 可提供更好的舒适度和改善的时空参数。然而，迄今为止，还没有提出根据患者踝关节损伤程度或机械/功能需求来调整 PD-AFO 刚度的定制原则。
