ISO 22675:2016 – Prosthetics: Testing of Ankle-Foot Devices and Foot Units

ISO 22675:2016 specifies the requirements and test methods for evaluating the mechanical performance of ankle-foot devices and foot units used in external lower-limb prostheses. The standard establishes standardized cyclic and static testing procedures that simulate the loading conditions experienced during the stance phase of walking, enabling manufacturers to verify the strength, durability, and service life of prosthetic components under realistic operating conditions.

The standard was developed to address the increasing complexity of modern prosthetic ankle-foot designs, many of which incorporate advanced materials and energy-storage mechanisms. By reproducing realistic gait loading conditions, ISO 22675:2016 provides a consistent method for assessing product performance and ensuring that prosthetic components meet internationally recognized safety and quality requirements.

Scope of the Standard

ISO 22675:2016 applies to ankle-foot devices and foot units used in external lower-limb prostheses. It specifies laboratory test methods for evaluating structural performance under both cyclic and static loading conditions that closely simulate the forces experienced during normal walking.

The standard is intended for conformity assessment and product verification. It is not intended to serve as a guide for selecting a prosthetic device for an individual patient.

Testing Requirements

The standard specifies two primary categories of mechanical testing:

• Cyclic (fatigue) testing to evaluate durability and service life under repeated walking loads.

• Static testing, including proof strength and ultimate strength tests, to verify structural integrity under maximum loading conditions.

The prescribed loading profiles simulate heel strike, mid-stance, and toe-off by applying standardized combinations of vertical and horizontal forces together with defined tibia angles, providing realistic assessment of prosthetic performance.

Safety and Performance

ISO 22675:2016 ensures that ankle-foot devices can withstand the mechanical stresses encountered during normal use while maintaining their structural integrity and functional performance. The standardized test procedures allow manufacturers to compare different designs using consistent evaluation methods and demonstrate compliance with internationally accepted performance requirements.

The standard supports the verification of strength, durability, and expected service life but does not assess clinical suitability, patient comfort, or rehabilitation outcomes.

Documentation Requirements

Manufacturers are required to maintain documented information demonstrating compliance with the requirements of the standard. Typical documentation includes:

• Product design specifications

• Material specifications

• Static and cyclic test reports

• Test configurations and loading parameters

• Performance evaluation results

• Quality control records

• Product labeling and instructions for use

This documentation provides objective evidence that the ankle-foot device has been tested in accordance with internationally recognized procedures.

Benefits of ISO 22675:2016 Compliance

Compliance with ISO 22675:2016 provides several important benefits, including:

• Improved safety and reliability of prosthetic ankle-foot devices.

• Standardized testing methods that realistically simulate walking conditions.

• Verification of product strength, fatigue resistance, and service life.

• Enhanced confidence among manufacturers, healthcare professionals, and regulatory authorities.

• Support for regulatory compliance and international market acceptance.

• Consistent evaluation of innovative prosthetic foot technologies.

• Improved product quality through repeatable and validated mechanical testing procedures.