Lower limb technical terminology


Adapters are prosthetic components used as connections between various functional components such as the knee or foot.

Donning aid

The donning aid is a hose-like sock that makes putting on the prosthesis easier. It is pulled over the residual limb so that the residual limb can be pulled into the prosthetic socket.

Bionic knee joint

This fully microprocessor-controlled knee joint system makes the absolutely intuitive use of the prosthesis possible. Numerous integrated sensors and complex measuring technology continuously determine the precise, correct setting of the knee joint. Bionic knee joint systems support a virtually physiological gait pattern and therefore relieve strain on the entire locomotor system.


Bouncing is bending under load against a dampening resistance up to a specific flexion angle.

Carbon prosthetic foot

Carbon is a very lightweight and robust material. It is also highly flexible and has a resilient spring effect. A prosthetic foot that is made primarily from carbon fibre is very lightweight as a result. Users benefit from the high energy return while walking.

Rotation adapter

The rotation adapter is a prosthetic component that allows the amputee to rotate the lower leg up from a natural posture. This can be very helpful in many situations, for example when putting on shoes.


The liner is a sock-like cover for the residual limb and acts as a sort of "second skin" between the movable soft tissue of the residual limb and the hard shell of the socket. It protects and cushions delicate and pressure-sensitive areas of the residual limb and connects the residual limb to the prosthesis. Selecting the right liner is essential in order to ensure the prosthesis fits well and is comfortable to wear. But a liner can only ensure optimum safety and comfort in combination with the right closure system that keeps the socket in place on the residual limb.

Microprocessor-controlled knee joint system

With this prosthetic knee joint system, a microprocessor with complex sensors recognises movement patterns and correctly adjusts the prosthesis in real time. It regulates the swing and stance phase so that the user can rely on the prosthetic knee joint.

Prosthetic foot

A prosthetic foot is an artificial foot that replaces the physiological foot. It always fulfils a specific, functional purpose and is individually selected for the user, tailored to his or her mobility. A prosthetic foot has a natural foot shape.

Prosthetic knee joint

A prosthetic knee joint is an artificial knee that serves as a functional replacement for the physiological knee. The various knee joints support the individual requirements according to the mobility of the amputee. We recommend our KneeSelect selection aid to choose the right knee joint.


The prosthetic socket joins your residual limb to the prosthesis and fulfils an important function: it ensures optimum adhesion and the proper fit of your prosthesis – which makes it crucial for acceptance and the wellbeing of the user. In order to achieve these objectives, the socket – depending on the shape of the residual limb and tailored to the mobility of the user – is individually fabricated.

Swing phase

The swing phase is the moment when the foot swings free in the air while walking.

Stance phase

The stance phase is the moment when the user is standing completely straight and bears weight on the leg without moving forward or backward.

Torsion adapter

A torsion adapter permits a rotation movement of the prosthesis without having to move the foot. It is installed above the prosthetic foot.

Vacuum system

A vacuum system is a negative pressure system that generates a vacuum between the residual limb, liner and socket using an "active principle" (pump) or "passive principle" (pistoning movement of the residual limb). The objective is good adhesion of the prosthesis on the body for a secure connection.


Yielding is flexion under load against a dampening resistance with unlimited flexion angle.

Mobility grade

Your level of activity plays an important role for the prosthetic fitting. This is why the following mobility grades have been developed in orthopaedics technology:

Low mobility grade

What are known as indoor walkers have a low mobility grade. They are able to cover short distances on an even surface and at low speed.

Moderate mobility grade

Restricted outdoor walkers have a moderate mobility grade. They are also able to walk on uneven surfaces and navigate low obstacles such as curbs and steps.

High mobility grade

Unrestricted outdoor walkers have a high mobility grade. They can walk on almost any surface and at various speeds, and also cover longer distances. Able to cross most obstacles, they can work as well as participate in therapeutic and other activities.

Especially high mobility grade

Unrestricted outdoor walkers with especially high requirements are able to master even more difficult challenges in sports, a work environment or during leisure activities with their prosthesis.