It is best to have a general understanding of all course materials for the CES test. However, from my experience with the exam, the vast majority of the test was centered around muscle actions (“which muscle essentrically decelerates knee flexion?, etc) and understanding all assessments, compensations, and progressions for the corrective exercise continuum. I would take the practice test a few times prior to taking the exam in order to get a comprehensive understanding of what will be on the final exam. So, things i would definitely know:
1. Muscle actions
2. Assessments (especially overhead squat)
3. Progressions/Exercise choices for compensations.
Hope this helps