X3: The world's most technologically advanced prosthetic leg

Above-Knee Prosthesis with: X3

No limits

The result of a collaboration between the US military and Ottobock, the X3 is quite simply the world’s most technologically advanced microprocessor prosthetic leg.

You may have a challenging or adventurous lifestyle. Or, you may simply want to keep up with everyday activities (showering, hiking, running to catch a bus) without having to worry if your prosthesis can make it through.

Click on the red “hot spots” in the photo to dig deeper into the advanced technology that will increase your mobility and your peace of mind.

Go to the Advantages for You tab below to learn how the X3 can transform the way you walk.

Robust protective cover

In order to withstand the many stresses of everyday life, the durable protective cover covers the knee joint and easily stands up to tough conditions. You can choose between two attractive design.

Inertial motion unit (IMU)

A gyroscope and acceleration sensors allow the position and speed of the X3 in space to be determined in real time. An angle sensor determines the flexion angle and flexion angle speed of the joint. Prosthesis control is based on movement analysis and additional force measurement.

Hydraulic unit

The hydraulic unit controls the Genium X3. The flexion and extension resistances are controlled independently by means of two control valves.

Knee moment sensor

The knee moment sensor supplies data about the knee moment and provides important information for precisely determining the forces acting on the prosthesis.

Inductive charging

The inductive battery charger is magnetically attached to the back of the knee joint – making easy charging through clothing possible.

Intelligent AXON tube adapter

The AXON tube adapter measures both the ankle moment as well as the vertical force acting on the joint in real time. The AXON tube adapter can be connected to a foot without a connecting piece.

Battery and electronics

In the X3, the rechargeable battery and electronics are enclosed and protected by the frame and protective cover. The integrated microprocessor coordinates all measurement and control processes.

What you need to know

Advantages for you

The most natural gait possible

An accelerometer and a gyroscope intuitively know where your leg is in space, using the same technologies from Wii™ gaming systems and smartphones, for a virtually natural gait. That means less worry of a stumble or fall and less concentration needed when you’re on the move.

Real-world mobility

More physical capabilities than any other prosthetic leg including running, walking backwards, crossing obstacles in a more anatomically correct way, and climbing stairs step-over-step without massive compensating movement. You’re always in control.


The X3 has undergone stringent waterproof testing. Completely submersible, the X3 allows unprecedented contact with water. Perfect for anyone working near water or for activities such as showering, washing your car, or boating. (Just be sure to clean it afterwards.)

Protective covers

We've added a simple "Assurance" cover (right) as a contrast to the original "Xtreme" cover (left). Ask your practitioner which is best for you. With either choice, you get the ultimate in rugged, waterproof performance. Both covers can be purchased separately, as an accessory.

Running on the X3 prosthetic leg.

Via the remote, the X3 switches into a larger swing angle for running and other sports. Plus, the innovative Walk2Run mode detects start-and-stop running (such as crossing a street or trying to catch a bus) and automatically increases your swing angle.

Robust and ready

The X3 is “ruggedized” based on conditions an active duty military member might face. That means it’s up to any challenging terrain you may encounter!

Keep going for longer

X3 offers improved battery life and an automatic “sleep” mode. That translates into five plus days of use without the need for a recharge, giving you greater independence.

Every step is smooth and secure

Choose a foot to complete your prosthesis -- these two are waterproof:

  • Triton Heavy Duty, robust and waterproof, for particularly challenging conditions), or
  • Triton Low Profile, with especially low structural height for those who need the extra room

5 activity modes

Five activity modes allow your choice of activities –biking, golfing, driving, and more – activated using a key fob-sized remote. Just strap on the remote control via its Velcro wristband – you’re ready to go!

How the X3 works

The X3 advantage: Optimized Physiological Gait (OPG)

How does it work?

(1) Preflex

The X3 maintains a hydraulically controlled 4˚ of preflexion of the knee joint when your heel starts your stride (“heel strike”), which allows your foot to reach full contact more quickly and gives you a more stable start to your step.

(2) Adaptive Yielding Control

Intelligent knee flexion (max. 17˚, depending on the situation) gives you more efficient, intuitive control of your prosthesis.

  • Because the knee is flexed it better absorbs shocks and helps limit future orthopedic problems.
  • Easy to take off with a quick step or side step.
  • Makes slopes and uneven terrain easier to handle, while reducing the need for you to make compensating movements.

(3) Dynamic Stability Control (DSC)

The heart of the system: DSC continuously samples multiple environmental inputs—including a gyroscope and 2-axis accelerometer—which determine the appropriate resistance (support) and release at any time during your walking cycle. That means optimum security for you.

  • Supports multi‑directional movement, so you can take quick steps— forwards, backwards, and sideways.
  • Increases stability when walking backwards.

(4) Adaptive Swing Phase Control

You get precise control of your lower leg no matter what your walking speed is. This also helps to prevent falls.

  • The quality of your swing phase (when your leg is off the ground) is far superior to other prosthetic knee joints.
  • It’s easier to swing your knee through during a stride, helping reduce the risk of stumbles and falls.
  • There are no limits on walking style: quick, slow, irregular— X3 handles it all.

Technical Info

X3 Specifications
Patient weight 275 lbs
Weight of knee 3 lbs 12 oz
Weight of the tube adapter 10.5 oz
Adjustable activity modes 5
Operating with fully charged battery Approx. 5 days
Knee flexion angle Max. 135 degrees


Take a look at our Frequently Asked Questions for more information.

Not finding what you are looking for? Please contact us.