Abstract
BACKGROUND: Ankle-foot orthoses (AFOs) are commonly prescribed to manage lower limb impairments, especially foot drop in neurological disorders. With the evolution of 3D technology, digital acquisition using 3D scanning and modelling using computer aided design software is becoming more commonplace to produce AFOs. Our previous systematic review in 2019 identified an emerging field of 3D printed AFOs and we highlighted biomechanical effects, mechanical properties and self-reported outcomes such as comfort. To cover the rapidly growing literature on the effects of 3D printed AFOs in clinical populations, the aim of this systematic review was to update an earlier review from 2019 to determine the feasibility and effect of 3D printed AFOs on biomechanical and satisfaction outcomes. METHOD: Seven electronic databases were searched from 1985 to July 2025. Original research papers of any design from healthy or clinical populations of any age were eligible for inclusion. Studies must have investigated the effect of 3D printed AFOs in healthy or pathological populations. The quality of the evidence was assessed using QualSyst. RESULTS: Twenty-eight papers were included in the updated systematic review. The use of 3D printing methods and materials varied markedly, where fused deposition modelling was more prevalent in recent literature than selective laser sintering, and Nylon 12 was most tested. The sample sizes were all smaller than 12. Walking speed and step length of people wearing 3D printed AFOs were mostly improved compared to those with other AFOs and shod or barefoot only. 3D printed AFOs generally had similar or higher satisfaction scores than traditional AFOs. Although levels of evidence were all lower than four, 10 papers had excellent study quality. CONCLUSION: The use of additive manufacturing in AFO fabrication has rapidly increased in the past few years. The novel designed 3D printed AFOs might have potential benefits over traditional designs in terms of biomechanical outcomes. 3D printed AFOs have been further proven to be comparable to traditional ones. Further research is encouraged to conduct with more specific condition characteristics such as cerebral palsy within a specific GMFCS level, longitudinal clinical trials and testing in a home or natural environment. Establishing a standard for AFO evaluation and reporting is also recommended.