A Multidimensional Index Framework for Evaluating the Regulatory Applicability of ISO 10328 Using a Prosthetic Knee Case Study.

International biomechanical standards, such as ISO 10328 for lower-limb prosthetic testing, are widely used to guide device evaluation, yet their direct adoption into national regulatory systems often results in mismatches in safety expectations, documentation formats, and contextual use conditions. Despite extensive reliance on ISO standards, there is no structured method to assess whether these standards are appropriately aligned with regulatory requirements across different jurisdictions. This narrative review, combined with a conceptual framework and an illustrative cross-jurisdictional case study, proposes a multi-dimensional applicability index designed to evaluate the regulatory fit of international biomechanical standards before national adoption. The index comprises five dimensions clinical safety alignment, technical fit, contextual usability, documentation conformance, and regulatory interoperability, each providing a structured lens for assessing standard suitability. Using ISO 10328 and a representative prosthetic knee device as an example, the study demonstrates how the index highlights areas of strong technical alignment but also reveals gaps related to usability, documentation, and post-market expectations across the U.S. FDA, EU MDR, and China's GB/NMPA systems. The findings underscore the need for context-aware evaluation tools to complement global standards, reducing approval delays and improving device performance in real-world environments. This work provides a foundational methodology for regulators, manufacturers, and standards bodies seeking to harmonize global testing norms while ensuring national regulatory relevance and patient safety.