Hydraulic & Pneumatic Knees

Hydraulic and pneumatic knees utilize air or fluid to adapt their behavior to different walking speeds as the wearer swings the leg forward and backward. Additionally, some designs allow the user to lock the knee for stability while standing for longer periods of time, or when walking in unfamiliar or unsafe environments.

Both pneumatic (air) and hydraulic (fluid) systems mimic the muscles of the natural knee by responding to varying walking speeds. Since they require fluid, hydraulic knees tend to be heavier than pneumatic knees, but they can also provide a smoother walking pattern across a greater range of speeds. Both hydraulic and pneumatic knees require frequent routine maintenance.

Hydraulic and pneumatic knees are best suited to moderately active people who want to vary their walking speeds. Your prosthetist will discuss the benefits and considerations and will help determine the best option for you.