AFO alignment affects knee joint, study finds

[Guest guest]

From BioMechanics July 2004

AFO alignment affects knee joint, study finds

By: R.

Conventionally aligned ankle foot orthoses increase demand on the knee

extensor muscles that can be ameliorated by realigning the device to

account for shoe heel height, according to results from a Chicago study.

Researchers from Northwestern University studied 12 patients with

hemiplegia after stroke (mean age 53) who participated in three gait

analysis trials, each two weeks apart. The first device tried was a

conventionally aligned (ankle at 90 degrees) thermoplastic articulated

AFO. The second was the same AFO realigned to account for the heel

height of subjects' shoes, and the third was a heel-height-compensated

AFO with a 3/4-length foot plate.

The conventionally aligned AFO was associated with a prolonged

dorsiflexion moment during early stance, a prolonged knee extensor

moment during single leg support and a slower rate of forward movement

of the center of pressure during the early phase of stance compared to

the other two AFO conditions. Average internal knee extensor moment was

increased for all AFOs compared to a shoe-only condition, but the effect

was most pronounced with conventional alignment.

The results were presented in April at the annual GCMAS meeting.

[Guest guest]

Thanks for this great article. Now I know what may be wrong with my knees,

they kill me after wearing my AFOs.