Article

An ankle-foot orthosis with an oil damper was previously developed to
assist the first rocker function during gait, but the effects of the amount of
resistive moment generated on gait have not been clarified. OBJECTIVES: To
measure the amount of resistive moment generated by the ankle-foot orthosis with
an oil damper during gait and determine its effect on the gait of patients with
stroke. STUDY DESIGN: Preliminary cross-sectional study. METHODS: The gait of
four patients with stroke in the chronic phase was measured in four conditions:
without an ankle-foot orthosis and with the ankle-foot orthosis with an oil
damper generating three different amounts of resistive moment. Measurements were
taken with a three-dimensional motion analysis system and a specially designed
device to determine the resistive moment. RESULTS: The resistive moment was
observed in the former half in stance of the paretic limb, and its magnitude was
less than 10 N m. Some gait parameters related to terminal stance and preswing
were affected by the amount of resistive moment. The forward component of floor
reaction force and the shank vertical angle showed peak values when the patients
reported feeling most comfortable during gait. CONCLUSION: Although the resistive
moment generated by the ankle-foot orthosis with an oil damper was small, it was
sufficient to alter gait. CLINICAL RELEVANCE: To maximize the effectiveness of
ankle-foot orthoses, it is necessary to know the effects of resistive moment on
the gait of patients with stroke. The ankle-foot orthosis with an oil damper
assists the first rocker function in gait and also affects the gait in a later
phase in stance. The peak values of some gait parameters coincided with patients
reporting gait to be most comfortable. It is important to know that ankle-foot
orthosis with an oil damper assistance in the first rocker alters the weight
acceptance on the paretic limb and affects the gait parameters related to propulsion ability in stance.

Langue : ANGLAIS