Above-knee and below-knee amputations are two of the most common levels of lower-limb loss, and the distinction between them has a significant effect on how a prosthesis is designed, fitted and used. Understanding the difference is a useful starting point before any detailed conversation about specific components or brands.
What differentiates the two levels
A below-knee, or transtibial, amputation occurs between the knee and ankle, meaning the natural knee joint is preserved. An above-knee, or transfemoral, amputation occurs above the knee, so the prosthesis must replace the knee joint itself in addition to the lower leg and foot. This single difference — whether or not the knee remains — has a considerable knock-on effect on socket design, component choice and the amount of functional training typically involved.
Below-knee (transtibial) prostheses
Because the knee is intact, a transtibial prosthesis generally focuses on a comfortable, well-suspended socket and a foot component matched to the person's activity level, from everyday walking to more demanding sport or work use. Many people find the transition to walking more straightforward at this level, since natural knee control is preserved, though residual limb shape, skin condition and socket fit still require ongoing attention.
Above-knee (transfemoral) prostheses
A transfemoral prosthesis needs a prosthetic knee joint in addition to a lower leg and foot, which adds mechanical and, in some cases, electronic complexity. Knee options range from simple mechanical designs to hydraulic or microprocessor-controlled knees that adjust automatically to walking speed and terrain. Socket fit is especially important here, since the socket must transfer body weight effectively through the thigh during standing and walking.
Why the distinction affects rehabilitation
Walking with an above-knee prosthesis is generally more demanding in terms of balance, energy use and training time than walking with a below-knee prosthesis, simply because more of the leg's natural function has to be replaced mechanically. This is not a reason for concern — it is a normal part of why rehabilitation plans, component selection and follow-up schedules are built around the individual's specific level and goals rather than a one-size-fits-all approach.