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 4.6
The person learns an exercise routine.
Splints can be taken on and off, but assistance tends to be needed for smaller adjustments.
The person may appreciate you incorporating your desired outcomes for joint mobility and strength into interesting functional activities.