BiOM Ankle

Reclaim your power

The BiOM Ankle is the only prosthesis with powered propulsion. It is characterised by the following clinically proven features:


  • Emulates the function of lost muscles and tendons (1)
  • Energises every step to walk farther and faster – even up ramps, hills and stairs (1,6)


  • Mimics physiological ankle movement
  • Ensures a centered alignment and a more natural stride (4)
  • Reduces joint forces which may result in less pain and fewer long-term orthopedic problems (1,2,5)


  • Dynamic resistance controls the ankle movement from heel strike until toe push off (1,4)
  • Provides balance on variable terrain (3)

(View full list of clinical studies in the section "Clinical References".)

Interested in BiOM? Contact us to book an assessment.

Rechargeable battery (lithium polymer)

Changeable battery on top, that lasts for 4 – 5 hours depending on user activity and weight. A dual bay charger can charge two batteries simultaneously in only 45 minutes.

Powered Propulsion

A battery-powered, motorized actuator coupled with a high energy spring provide powered propulsion that emulates the gastrocnemius and soleus muscles.

Dynamic Adaptation

Intrinsic control firmware analyzes ankle joint torque and angle data from high resolution sensors, in real-time, to mimic the user’s physiological ankle function.

What you need to know...

Advantages at a glance

Covering longer distances in less time

The BiOM Ankle provides the exact amount of propulsion needed for every step you take. In doing so, weight is distributed gently over the remaining limb, allowing you to conserve energy. This means you are less fatigued, so it is easier to cover longer distances in a faster walking speed.

Coping better with everyday life

In everyday life, ramps, slopes and especially stairs repeatedly pose challenges. It takes a great deal of energy to compensate for missing muscle functions. This is where the BiOM Ankle comes into play, restoring the propulsion which is needed for forward and upward motion. This enables you to cope effortlessly with stairs and sloping terrain.

Safety and stability on different terrains

The BiOM Ankle stabilises your movement as its decelerates the body during rollover of the foot before accelerating again for toe-off. In addition, the entire surface of the foot lowers itself immediately to the floor. You can control every step regardless of the surface, which gives you a secure feeling.

Gentler on joints

Many users suffer from painful joints as a result of changing their gait pattern. Unbalanced movement patterns and compensatory movements can even lead to osteoarthritis. With its active powered propulsion, the BiOM Ankle improves your gait pattern. This helps to prevent joint pain as well as long-term orthopaedic problems.


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Information for user

This brochure presents the most important BiOM Ankle information from a user’s perspective.


The BiOM Ankle mimics your lost muscle functionality when you walk, resulting in a more physiological gait pattern. A unique feature is the powered propulsion of the foot, providing high-energy support for every step. In this way, the foot and entire body are propelled forwards. The required energy is supplied by a battery mounted on the prosthesis. At the same time, high resolution sensors regulate the intensity of the forward thrust and the foot position you need for the relevant situation.

Clinical References

1. H. Herr, A. Grabowski, ‘Bionic ankle–foot prosthesis normalizes walking gait for persons with leg amputation’, Proc Biol Sci. Vol. 7, 279(1728): 457–464. 2012.

2. A. Ferris, J. Aldridge, J. Sturdy, J. Wilken, ‘Evaluation of the Biomimetic Properties of a New Powered Ankle-Foot Prosthetic System’, Dept. of Orthopedics and Rehabilitation, Center for the Intrepid, Brooke Army Medical Center, Fort Sam Houston, TX, USA. Presented at American Society of Biomechanics 2011.

3. D. Gates, J. Aldridge, J. Wilken. ‘Kinematic comparison of walking on uneven ground using powered and unpowered prostheses’, Clinical Biomechanics, 28, 467–472, 2013.

4. J. Aldridge, A. Ferris, J. Sturdy, J. Wilken, ‘Kinematics and Kinetics with a Powered Lower Leg System During Stair Climbing Ascent Following Transtibial Amputation’, Gait & Posture, Vol. 36, 291–295, June 2012.

5. A. Grabowski, S. D’Andrea. J., ‘Effects of a powered ankle-foot prosthesis on kinetic loading of the unaffected leg during level-ground walking’, Neuroeng Rehabil., 10:49, 2013.

6. E. Esposito, et al., ‘Step-to-step transition work during level and inclined walking using passive and powered ankle-foot prostheses’, Prosthet Orthot Int. 2015 Jan 27.


  • Who is the BiOM Ankle for?

    The BiOM Ankle is for people with above or below the knee amputations who are low to moderately active and want to maintain an active lifestyle. It is suited to a body weight up to 130 kg and available for foot sizes 25-30cm.

  • How long does the BiOM battery last?

    The battery lasts four to five hours, depending on intensity of use. It is therefore quite likely that you will need to replace the battery during the course of the day. Two batteries can be charged simultaneously in a dual bay charger within 45 minutes. When battery power is low the Ankle will vibrate indicating that the battery needs to be changed or charged soon.

  • Can I swim or take a shower with the BiOM Ankle?

    No. But the BiOM Ankle is weatherproof and therefore protected against splashed water. So a sudden shower during a walk is no problem.

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