Gait Knee¶

stance phase 60%
flexion-extension-flexion

swing phase 40%
extension

initial contact
extension (-2 to 5°flexion)
-The knee can be hyperextended to -2°
•This means that the knee has to have a convertible knee joint wich can variate from 4° to -2°

by keeping knee extended we keep stability

loading response
flexion (15°)
shock absorption
-The center of gravity changes. The weight is changed to the leg which the individual is going to use.
•The knee need to handle the weight so the knee does not collapse.

mid stance
5°increased flexion, then extends to 12°flexion
to keep stability

terminal stance
completion of extension, then flexion starts again at the end.

pre swing
flexion(up to 40°)
to prepare for the swing

swing
extension

must have
hinge joint

2motors (flexion and extension)
2 degrees of freedom

strong build, must be able to carry weight.
easy to remove and put on, same system as with össur.
sensor for angular postion

good to have
rotation in the knee

people with prostetics have more knee flexion

implementation
simple hince joint.

rotation in knee
there has to be some rotation in the knee, otherwise it would be torque in the joint.
easiest to have the rotation below the knee