Overview
ISO/TR 22676:2006 is a Technical Report that provides guidance for testing ankle-foot prosthetic devices and foot units in conjunction with ISO 22675. It focuses on the specification of test loading conditions defined in ISO 22675 and on the design of appropriate test equipment, supplying the theoretical background and practical design considerations that would otherwise lengthen the main standard.
Key Topics
This guidance document addresses the technical elements required to implement reproducible prosthetics testing:
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Application of ISO 22675 test loading conditions
- Guidance on directions and magnitudes of heel and forefoot reference loading for static and cyclic tests.
- Clarification of force components, their lines of action, and time profiles used to simulate gait loading.
- Reference test loading levels (e.g., P3–P5) and associated profiles for test reproducibility.
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Test equipment design and mechanics
- Detailed recommendations for foot platform kinematics, including the role of the tilting axis (TA), elevation (E) and anterior–posterior (A–P) displacement (Δf), and their effect on the applied loads.
- Design variants for load application, with practical examples such as asymmetrical (60:40) and symmetrical (50:50) crank gear drives to generate tilting angle profiles γ(t).
- Consideration of top load application point P, its dependence on foot length (L), and methods to transpose P to compensate geometry differences.
- Analysis of moments, driving torque, and effects of deviations from specified tilting profiles on test forces.
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Analytical and illustrative material
- Figures and tables illustrate force profiles, crank geometries, positional effects, and numerical examples (e.g., Table 1 for resultant force magnitudes).
Applications
ISO/TR 22676 is practical for professionals involved in prosthetics testing and development:
- Prosthetic device manufacturers - to design test rigs and verify ankle-foot devices and foot units under standardized loading conditions.
- Biomechanical test laboratories - to implement ISO 22675 tests with properly designed machinery and reproducible loading profiles.
- Design engineers and R&D teams - for understanding how platform kinematics and load application influence test results.
- Regulatory and conformity assessment bodies - to interpret test methods and ensure consistent application of ISO 22675.
Related Standards
- ISO 22675 - Primary standard specifying test methods for ankle-foot devices and foot units (ISO/TR 22676 is guidance for applying ISO 22675).
- ISO 10328 - Related prosthetics structural testing standard referenced for comparative values and concepts.
- Developed under ISO/TC 168 (Prosthetics and orthotics).
Keywords: ISO TR 22676, prosthetics testing, ankle-foot devices, foot units, test loading conditions, ISO 22675, test equipment design, heel and forefoot loading, cyclic and static tests, crank gear, tilting axis.
Open preview (PDF)Prosthetics — Testing of ankle-foot devices and foot units — Guidance on the application of the test loading conditions of ISO 22675 and on the design of appropriate test equipment
