Concept VGK

Features and benefits of the VGK concept

Energy independence

Amazing though it might seem, a VGK performs its functions without batteries, instead it generates power inside to dynamically operate the valves. You can go about your business as long as you need or set out on a journey without ever worrying that the knee unit might all of a sudden malfunction.

walking downstairs

VGK is not the only knee unit to allow the prosthesis to walk leg over leg downstairs. However, it is an energy-independent hydraulic knee unit with polykinetic processor, whose bending resistance changes dynamically during each step due to the patented fluidic technology. It means that you will be walking downstairs with a sweep, and each prosthesis bending will be uniform with no acceleration and dip effect at the end of the step (without the so-called “clasp-knife effect”). 

speed variation

At a glance, it is as simple as that: the faster you walk, the faster a VGK works. It is the hydraulic system that auto-adjusts to walking pace securing the foot to be in time ahead of you.

stumble recovery

When do we run the risk of stumbling? Very often: for example, when we are walking and are engrossed in a conversation with someone, or when we are lost in thoughts about something, or when we are admiring the surroundings. The surface we are walking on may not be absolutely smooth. In case you stumble the Stumble Recovery function will help you avoid tumbling. The equivalent of this polykinetic processor function can also be found in some microprocessor knee units.

thermal stability

The patented fluidic technology guarantees a steady operation of the VGK at different temperatures of both the environment and the knee unit. It means that you can walk for a long time at a fast pace (particularly down the stairs or slopes) without worrying about temperature setting modification as the knee unit heats. Alternatively, you can visit regions with a cold or hot climate, and practically see no difference in the VGK operation mode. This property is underpinned by the Vortex Metering System (VMS).

stability under load

The patented hydraulic technology allows maintaining the VGK settings at different loads on the prosthesis. It means that if you go on a backpacking trip or have to bear a heavy load, the VGK will adjust to the changed conditions, and you will practically see no difference in the VGK operation mode.

stable stance phase

If necessary, you can select the Ultra High Resistance operation mode. What for? For example, you would like to go fishing, or to take a picture, or you have to work standing up – this VGK operation mode will secure safe standing.

cycling mode

To go cycling you choose the Cycling operation mode.

water resistance

The VGK is a water resistant device. Even if you are caught in the rain and get soaked or have to wade through waters, the knee unit will still be functioning.

walking downslope

The VGK enables you to walk leg over leg down sloping surfaces. Moreover, the patented fluidic technology guarantees smooth walking and steady operation mode of the knee unit. 

walking through grass

If you lead an active lifestyle and travel a lot, you definitely faced a situation when you have to go through a terrain with thick grass or wade through shallow water. It may really turn out to be a challenging task as the knee unit bends uncontrollably when moving the prosthesis through grass or water. The VGK-Go! in particular helps to solve this problem and enables you to move steadily.


The VGK has the maximum bending angle, actually limited only by the prosthetic socket. It allows you to get on your knees or even sit down when you are playing with a child, working, or performing a religious ritual.


The build height of a knee, above the knee centre, matters for cosmetic results. VGK-Go! is designed to minimise this build height. For details see manual.