Foot Orthosis

Foot Orthosis

Design for ISO testing compliance

Design for ISO testing compliance 
While developing foot orthosis to meet ISO testing, it is important to select standards that provide safety and effectiveness in usage. Compliance is usually with standards like IS0 22675, ISO 13485 (Medical Devices-QMS), and ISO 10328 (lower limb orthotic device structure testing). To ensure the foot orthosis design meets ISO testing standards, the following tests have been considered in the design and material selection:

  1. Structural Integrity and Load Testing (ISO 22675)

Objective: The orthosis should sustain forces and load cycle levels characteristic of walking and general movement without structural failure or decline in overall capacity.
Design Specifications:

  • Load-Bearing Capacity: The orthosis has to bear the user’s weight, and the optimum factor of safety against peak loads has to be considered.
  • Fatigue Resistance: Materials chosen have to be capable of withstanding stress and strain which results in fatigue failure. Materials must be capable of withstanding at least two million cycles.
  • Environmental Resilience: Both the structure and the material should be protected from dampness, temperature fluctuations, and wear from outdoor and indoor applications.


  1. Types of materials used in product design and its biocompatibility (ISO 10993)

Objective: Make sure that any material a patient comes into physical contact with does not have the potential to cause a rash, poisoning or an adverse immune response.
Design Specifications:

  • Biocompatibility: There is no use of any toxic materials, all materials that are used are hypoallergenic and are tested for biocompatibility as per ISO 10993.
  • Chemical Stability: The parts of the orthosis are not affected from sweat, oils and regular cleansing means and products.
  • Softness and Cushioning: To prevent the formation of pressure ulcers, padding is provided where high weight is asserted, with materials that provide cushioning without compression. For that reason, extending the protective properties of a given material without compromising cushioning is vital in eliminating pressure sores in the treating areas of the client.


  1. Dimensional Accuracy and Fit(ISO 10328)

Objective: To maintain accurate and identical manufacturing dimensions for a right interface fit and appropriate biomechanical support.
Design Specifications:

  • Custom Fit Geometry: The orthosis is to fit the general shape of the patient perfectly and should be adjustable to accommodate slight differences.
  • Tolerance Control: To prevent problems related to loosing or instability, parts are made with utmost precision that is, with specific tolerance.
  • Alignment Stability: Interferences and anatomical references are positioned and shaped to have its corresponding mechanical performance and stability during utilization.


  1. Quality Assurance and Durability Testing (ISO 13485)

Goal: Create a strong quality management system to guarantee constant product dependability and quality throughout production.
Design Requirements:

  • Process Validation: To make sure every device satisfies requirements, manufacturing procedures are checked for consistency.
  • Durability Testing: To ensure material integrity, prototype models are subjected to simulated wear and tear tests that mimic real-world use scenarios. Periodic stress testing is also conducted.
  • Documentation and Traceability: Every component can be linked to its production batches and raw materials, enabling quality control and, if necessary, recall capabilities.


  1. User Safety and Risk Mitigation (ISO 14971)

Goal: Determine and reduce hazards to patient safety while in use.
Design Requirements:

  • Analysis of Risk: Potential failure modes like structural failure, material deterioration, and inappropriate fit are identified by a thorough risk assessment, and each is addressed with design changes.
  • Instructions for Users: To reduce abuse or damage to the orthosis, users are given clear usage instructions and maintenance advice.
  • Failure Mode Testing: To identify and fix any crucial design elements, components are put through controlled failure testing.