Harmony P4 vacuum system

A faster and stronger solution for socket comfort

The new and improved Harmony P4 combines superb vacuum suspension with torsion and vertical shock into a compact package. That gives amputees with longer residual limbs access to the outstanding suspension of Harmony vacuum while enjoying the benefits of rotation and shock absorption. Compared with Harmony P3, the Harmony P4 reaches full vacuum quicker than ever, giving amputees a heightened sense of comfort and security and combines a sleek and slender design with interior power and performance. In addition to the existing direct lamination version, the new Harmony P4 4-hole allows modular integration into the prosthesis and direct P2/ P3 replacement.

Harmony P4 has a whole host of proven clinical benefits. These include:

  • Limb volume management, which can reduce the need to add socks
  • Reduces pistoning between the limb and the socket
  • Improves residual limb health
  • Helps improve balance and reduces the risk of falls through improved walking.
  • It's compact design allows for a wider range of prosthetic feet to be prescribed.
  • Double-stroke technology generates vacuum in just a few steps
  • HD version is suitable for a body weight of up to 150 kg

What you need to know

The Harmony solution

Do you have a problem with your prosthesis? We’ve got the solution!

Is your prosthesis ever uncomfortable? Does your socket seem to get looser over the course of the day? Does your leg feel poorly ‘connected’ to your prosthesis?

These issues can come from volume changes in the socket. Just like a shoe that’s the wrong size, it can lead to painful skin problems limiting your activities.

The style of socket can also make things worse for some amputees. Conventional Specific Weight Bearing Sockets can cause fluid loss by forcing fluids out of the limb during walking, while simultaneously reducing the surface area that distributes pressures.

To make up for the changes in limb volume, many users add socks to their residual limb during the day but this doesn’t get to the root of the problem: the loss of fluid and volume fluctuations.

Intimate fit begins with the right socket

Conventional sockets force your leg to conform to the shape of the socket, and can create pressure peaks in sensitive areas. A Total Surface Weight Bearing socket (TSWB) on the other hand, supports your weight through the entire surface area, rather than specific targeted areas which often leads to sores and abraisions.

It’s like the difference between walking in a shoe that fits perfectly versus a shoe two sizes too big; even if you add enough socks, it will feel sloppy and may cause blistering.

The perfect liner

Our Uneo Anatomic 3D liner material (made from polyurethane) flows from areas of high pressure to low pressure which regulates and distributes pressure evenly. The socket then feels like it contacts you evenly all over, making for the ultimate in socket comfort.

Adding vacuum for amazing connection and comfort!

Add the TSWB socket to the Harmony’s active vacuum, and you’ll find that your leg is drawn more completely into the custom socket. This creates a more intimate fit, and allows fluids to be more easily drawn back into your limb when you’re walking.

You’ll feel the difference immediately:

  • Improved comfort and stability
  • Enhanced connection, or ‘linkage’ will help you feel where your leg is in space (proprioception)
  • Walk more naturally: by allowing you to spend more time on your prosthetic side
  • It may even help maintain skin health by increasing fluid flow

Handle any bumps in the road: torsion and shock absorber

The benefits of torsion and shock absorption minimise compensatory movements, reducing aches and pains. Shock absorption also helps to reduce back pain and releives sores and abrasions.

Proven benefits

Limb volume management

The volume of an amputee’s residual limb can change over the course of the day thus changing the fit of the socket. The Harmony System prevents these volume fluctuations and the prosthesis always remains securely in place.

Reduces pistoning

Movement can occur inside the socket causing the end of the residual limb to repeatedly collide with the socket, (known as pistoning) resulting in damage to the skin around the end of the residual limb. The Harmony keeps the prosthesis securely in place which minimises movement in the socket.

Improves residual limb health

With pistoning reduced through the use of an Active Vacuum solution, the residual limb endures less of the punishing movements that can jeopardise the overall health of the residual limb.

Helps improve balance

According to studies, an improved socket fit and comfort will give amputees an increased send of balance, and in turn a reduced risk of falls with improved walking.



Harmony P4

Download the brochure for the Harmony P4 Active Vacuum system.

Related systems

Harmony P3 vacuum system

The vacuum system with the mechanical Harmony P3 pump provides good adhesion in the prosthetic socket that minimises impacts and tensile forces.


Harmony E2: Electronic vacuum pump system

The Harmony E2 is an electronic pump option for the Harmony System, a proven and established active volume management system for amputees.