Description

Variable friction utilizes a fluid control system (hydraulic or pneumatic) to control the amount resistance to knee bend.  As knee bend increases, resistance increases and vice versa.

Advantages

  • Progressive resistance as knee bends.
  • Can be found in both monocentric (single axis) and polycentric (multi axial) knees.
  • More natural gait.
  • Can be adjusted to allow for a range of cadences.

Disadvantages

  • Can be expensive.
  • Heavier and more complex than other systems.
  • Requires accurate adjustment by trained practitioner.
  • May require periodic adjustment.

Common Components

Otto Bock

Ossur

Blatchford

Medi