Passive vacuum socket suspension system
An overview of the working principle of the passive vacuum approach, which aims to support retention within the socket by making use of the stepping movement itself.
What is passive vacuum suspension?
Passive vacuum suspension is a socket attachment approach that aims to create a negative pressure environment by managing the enclosed air volume between the residual limb and the socket through the walking movement itself. This environment aims to help the limb stay more stable inside the socket.
Unlike active systems, there is no electric or mechanical pump to evacuate the air; the creation and maintenance of pressure rely on the change in load applied to the socket during the step.
The suitability of the approach is determined only through the assessment of the physician and the clinical team, according to factors such as the condition of the residual limb, skin health and the person's mobility level.
How is negative pressure maintained?
The residual limb is usually covered with a soft liner, and the space between the socket and the liner is kept airtight by means of a one-way air valve. As the limb settles into the socket during the step, air in the space is expelled; when the load is removed, the valve prevents air from re-entering, helping to maintain negative pressure.
- Creating an enclosed air volume with a liner and an airtight seal
- Expelling air from the volume through a one-way valve during the stepping movement
- Attempting to maintain pressure when the load is removed
Key aspects of the approach
The headings below are for general information; individual results vary according to the person and the clinical assessment.
Pump-free operation
Because the creation of pressure relies on the stepping movement, the aim is that no separate electric or mechanical pump mechanism is needed.
Adapting to volume change
It is intended to help stabilize the connection when small changes occur in residual limb volume during the day.
Skin–socket contact
It works toward more consistent contact between the limb and the socket; this may help in managing load distribution.
Perception of movement
A stable position of the limb inside the socket may support feedback about the position of the prosthesis during the step.
Simple structure
As an approach that works with a small number of components, it is intended to keep the parts that need to be monitored in daily use limited.
Integration with the liner
Compatible operation of the liner that provides the seal and the valve aims to help maintain the connection throughout the day.
Related suspension approaches
Different suspension approaches address different needs. Which method is appropriate is assessed individually by the clinical team.
Active vacuum suspension
An approach that aims to create continuous negative pressure inside the socket by means of a mechanism that evacuates the air.
Pin-lock suspension
An attachment approach based on a pin at the end of the liner engaging with a locking mechanism inside the socket.
The fitting process
Physician's Assessment
The process begins with a specialist physician's assessment and a prescription/medical report.
Measurement and Fitting Trial
The condition of the residual limb is assessed; the appropriate liner, socket and valve placement are planned.
Fitting and Adaptation
The system is fitted; the seal and valve settings are adjusted individually.
Follow-up
Training in use is provided; regular follow-up is provided for check-ups and adjustments when necessary.
Frequently asked questions
Is passive vacuum suspension suitable for everyone?
Suitability depends on factors such as the condition of the residual limb, skin health and mobility level, and is determined only through the assessment of the physician and the clinical team.
What is the difference between passive vacuum and active vacuum?
In the passive approach, negative pressure is created by the stepping movement and there is no separate pump; the active approach includes a mechanism that evacuates the air. Which is appropriate is assessed individually.
Does the system require maintenance throughout the day?
It is recommended that the condition of the seal, the valve and the liner be reviewed regularly. Care and method of use are explained by the clinical team.
This content is for informational purposes; please consult your physician for diagnosis and treatment. Applications are carried out at our licensed center locations in line with a specialist physician's prescription/medical report.
