Joints are classified according to the amount of movement possible between the articulating surfaces.关节的分类是以关节活动度的大小为依据的。Temporomandibular joint disorders usually involve pain or restricted joint movement.颞颌关节病通常会导致疼痛和关节活动受限。It's important to keep the joint mobile while it heals.在关节痊愈时，保持关节活动是很重要的。