I have seen from the Shepherd books/questions having MAS of 2 or higher being when “stop” AFOs should be considered. However, the question information should be used as well, such as if the foot is having trouble with consistent placement or if the spasticity leads to something. I agree with Chrissy above with the 3-4 on the MAS being “severe”. Really just focus on what the patient is having trouble within gait and make sure the answer choice is doing that to the best of its ability while also not being soooo restrictive.
