Powered (active) ankle-foot system
Information on powered prosthetic foot systems that move the ankle under electronic control and aim to generate active push-off during the step.
What is a powered ankle-foot system?
A powered ankle-foot system is a type of prosthetic foot that aims to generate active movement and push-off during the step with the help of a motor and power source placed in the ankle area. Unlike passive carbon-fiber feet, it aims to obtain part of the push-off force from the motor in addition to stored energy.
The system works together with sensors that detect the phases of gait and a control unit that processes this data. The aim is to adapt the position of the foot to step speed and the ground during the heel strike, rollover and toe-off phases.
This product group is assessed by taking into account the person's activity level, physical characteristics and daily living needs. The suitability decision and all settings are determined by the prosthetic team in line with a specialist physician's prescription.
The sections below have been prepared to introduce the general operation of this technology; the contribution of each feature to a person is assessed individually.
Key functions
The headings below introduce the general functions of this product group; suitability for the person and the expected contribution depend on individual assessment.
Active push-off
Motor-assisted drive aims to contribute to the step during the toe-off phase.
Gait phase detection
Sensors detect which phase the step is in and try to adapt the position of the foot.
Adaptation to step speed
The control unit aims to adjust movement according to different walking speeds.
Adaptation to ramps and slopes
Changing the ankle angle according to the slope of the ground aims to increase support on inclined surfaces.
Power source and indicators
Operates with a rechargeable power source; the remaining charge can be monitored through status indicators.
Adjustable control
Parameters can be configured for the individual and adapted from everyday use to more active use.
Operating principle
At the core of the system are a motor that moves the ankle, a control unit that manages the movement and sensors that collect step data. These components work together to try to ensure that the foot takes a suitable position with each step.
Powered drive aims to provide an additional contribution to the energy stored by a passive spring element. In this way, the aim is for the ankle to behave differently in situations such as walking on level ground, going up a ramp or rising from sitting.
- Motor unit that moves the ankle
- Sensors that monitor the step phases
- Electronic control that manages the movement
- Rechargeable power source
Daily use and maintenance
Since powered systems run on a power source, they require regular charging. Before use, the charge level and the operation of the components are checked; if any change is noticed, consulting the practitioner is recommended.
Topics such as conditions of use, cleaning and contact with water differ for each component. For this reason, daily use rules should be assessed according to the information provided by the team fitting the device.
How do suitability assessment and adaptation proceed?
Physician's assessment
Amputation level, general health and mobility goals are assessed by a specialist physician.
Measurement and fitting trial
A suitable socket and alignment are prepared for the individual; the fit of the system is observed during the fitting trial stage.
Parameter settings
Control settings are configured according to step speed, ground and usage habits.
Training and check-ups
Information is provided on use and charging; check-ups at regular intervals are recommended.
Frequently asked questions
Who is a powered ankle-foot system suitable for?
Suitability is assessed individually by the specialist physician and prosthetic team, taking into account the person's amputation level, activity level and needs.
What is the difference between a powered system and a passive foot?
Passive feet work only with the energy stored by spring elements; powered systems additionally aim to generate active push-off by means of a motor. Which option is suitable depends on individual assessment.
How often is charging needed?
The charging requirement varies according to intensity of use and the component; details are clarified through the information provided by the team fitting the device.
Is it resistant to water and harsh conditions?
Durability and conditions of contact with water differ for each component; conditions of use should be assessed according to the information provided by the practitioner.
This content is for informational purposes; consult your physician for diagnosis and treatment. Fittings are carried out at our licensed center addresses in line with a specialist physician's prescription/medical report.
