Standby assistance during exercises is required when the person has had a medical problem that has secondary consequences, e.g. hip and knee replacements, unhealed fractures, etc. They are not apt to comprehend the consequences, nor are they apt to follow precautions.
ACL 4.0 - 4.2
One action at a time may be followed in range of motion and strengthening exercises. Their counting of repetitions may be limited to 5 or 10. Someone will need to demonstrate the motion, count with them, and correct improper positioning.