Wool does this despite shrinkage and felting which cannot be eliminated entirely if its other properties are to be preserved. New prosthetic sockets fit more precisely, and amputees are more active. Thus, skin condition, flexibility, and greater consistency of sock thickness are becoming more important. To create fulling, these fibers are used with Lycra spandex, the same elastomer that conforms bike pants and swim suits to the body. Lycra pulls knitted yarns together to thicken the fabric for socks that are easier to care for, have stretchability, and enhance skin protection.
Cotton absorbs moisture but holds it in the fabric, making the sock stay wet and feel clammy.
Wicking fibers offer a better solution for removing perspiration from the skin and cooling it. However, if you need to bleach your sock, select cotton. Cotton is the only fiber that can be bleached. No matter which fiber you choose, you must still rely on ply for daily changes in residual limb size due to edema or atrophy. In specifying prosthetic socks for veterans, VA requires manufacturers to use wool yarns of a particular size.