Advantages of using a stump sheath
Stump sheaths tend to offer the most benefit when used for the purpose of wicking perspiration. The nylon used to manufacture sheaths is non-absorbent and allows perspiration to move through the sheath and be absorbed by your prosthetic socks. If your prosthetic sock system incorporates socks made with Coolmax, you can also expect to stay cooler in the summer and warmer in the winter.
Additional benefits can be reaped for those experiencing abrasions or friction related to socket pistoning. Nylon's slick interface reduces friction caused by loose sockets and heavy sweating. Anecdotally, 70% of below knee amputees vs 35% of above knee amputees claim to experience a "comfort benefit" from wearing stump sheath.