Grade I: Small amplitude movement at the beginning of the range, used to relieve pain without stretching the tissues.
Grade II: Moderate amplitude movement within the mid-range of the joint, helping to reduce pain and stiffness.
Grade III: Large amplitude movement that stretches the joint capsule and surrounding tissues, used to increase range of motion.
Grade IV: Small amplitude movement at the end of the range, primarily used to improve joint flexibility by stretching the joint capsule.