Response to Question #65: Our reference for this question was the Effgen text (most recent 2nd edition, page 328). A young child (in the case a 4yo) with 3/5 strength in hip flexion/adduction and knee flexion/extension, and 2/5 hip ABD strength should be able to manage standing and ambulation in the classroom and school building with AFOs (may possibly need an assistive device as well). Keep in mind that this question is written in the preschool setting, therefore, the task demands are restricted to that environment.
I agree with the quote from Campbell that a child with 3/5 quadriceps strength sometimes needs KAFOs, especially an older and heavier child. Orthotic prescription in Myelo is not an exact science so these questions are hard to write. In the real world of practice there is a bit more problem-solving to do.
When taking the PCS exam, be sure to also consider the child’s age, task demands, setting, and any other contextual factors related to the question (especially more subtle ones).