A recent study noted that while AFOs have been shown to improve gait and static balance in people with lower-limb weakness and instability, effects of AFOs on dynamic balance reactions are not well known. Therefore, researchers set out to determine the effects of an AFO on reactive stepping responses in healthy young adults. The study concluded that AFO use can influence reactive stepping limb preference and stepping limb kinematics in healthy young adults, which can inform future research on AFO users with gait impairments. They results may also be helpful in developing interventions to address the specific effects of an AFO on reactive stepping responses.
Twenty adults completed ten reactive stepping trials using a lean-and-release system for three AFO conditions: no AFO, AFO on left leg, and AFO on right leg. Trials were recorded using 3D-motion capture and force plates. Stepping limb preference and temporal, spatial, and kinematic variables were measured.
With no AFO, the participants demonstrated a preference for stepping with the right leg (7.0 ± 3.9 of ten trials). With an AFO on the right leg, this preference decreased to 5.7 ± 4.4. With an AFO on the left leg, the preference increased to 8.1 ± 3.3.
Reaction times were not significantly different between conditions, but participants took a significantly shorter reactive step with the leg wearing the AFO. Peak ankle, knee, and hip joint angles were significantly less with the AFO on the stepping limb compared to the stance limb.
The study, “Impact of an ankle foot orthosis on reactive stepping in young adults,” was published in Gait & Posture.