There are three types of range of motion: passive, active, and active assisted.
Passive range of motion is when your joints move without any muscular contraction. An example of this would be if someone else moved your arm for you. Active range of motion is when your muscles contract to move your joints. An example of this would be if you lifted your arm up on your own. Active assisted range of motion is a combination of the two previous types; it occurs when your muscles contract to help move a joint that’s being moved by another force (usually passive). An example would be if you used your bicep to help curl a dumbbell that was too heavy for you to lift on its own.
All three types of range of motion are important for different reasons. Passive range of motion helps maintain normal joint function and prevents stiffness, while active and active assisted movements help keep muscles strong and prevent atrophy (muscle loss).