When we think of the latest and greatest prosthetic limbs, our minds often automatically focus on computerized knees, feet, and hands. In reality, the newest and greatest developments actually revolve around the way the prosthesis fits. The most advanced components are only useful if the prosthesis fits properly and comfortably.
The prosthetic socket is the portion of the prosthesis that the residual limb fits into. It is custom made, based on an actual mold of the residual limb. Creating a well-fitting socket is a meticulous science, where the prosthetist ensures each area of the limb experiences the appropriate level of compression and relief. When a prosthetic user’s limb changes, that intimate fit can be compromised.
Some common symptoms of a poorly fitting socket may include:
- Not being able to fit the limb completely inside the socket, leaving a gap at the bottom
- Feeling like the limb is moving inside the socket, causing instability
- Feeling like the limb is slipping in and out of the socket (pistoning)
- Feeling pressure at the bottom of the limb, due to ‘bottoming out’
- Bruising at the end of the limb or knee cap
- Due to not fitting all the way into the socket, the prosthesis feels too tall
- Due to volume loss in the residual limb, it fits further inside the socket and the prosthesis feels too short
Socket adjustments, padding, and sock ply (thickness) management are ways to compensate for gradual changes in the residual limb. Significant changes in the residual limb, however, will require a replacement socket. At this point, the prosthetist would recommend a new socket created from a new mold of the residual limb.
If you have questions about socket fit, contact a prosthetist who can guide you through the process of achieving a socket fit that meets your needs.