Prosthetic liners made of solid elastomer like silicone, copolymer gel, or polyurethane have been commercially available and used for a number of years as the media next to the skin in the majority of lower extremity prostheses.
Such liners have solved many issues like friction and pressure distribution; however, it has been difficult to achieve effective heat and sweat management when using a non-porous interface. For instance, moisture (e.g. sweat or condensation) within the liner can adversely affect limb health. Moisture decreases the friction suspending the liner on the residual limb. This can cause a pistoning action, which describes the relative movement between the liner and the residual limb.
Excessive limb pistoning tends to lead to friction-related injuries such as friction blisters and skin irritation. It also creates the potential for catastrophic failure of the suspension of the limb. Problems such as dermatitis and infection are also common, particularly if the liner and residual limb are not cleaned appropriately or frequently.
Attempts have been made to incorporate elements such as drain systems, heat exchangers, and semiconductors into known liners and/or prostheses to more effectively remove heat and sweat from the liner interface, yet, such designs are relatively complex, bulky, costly, and inevitably prohibit their use with a large majority of users.
To prevent such problems and to maintain secure adherence, users or amputees are currently required to manage the build-up of sweat in the liner themselves. They regularly have to remove their prosthesis to empty accumulated sweat and dry their limb.
There is thus a need for a prosthetic socket system that provides simple, comfortable, and effective heat and moisture management without removal of components of the system.