Final answer:
A partial or incomplete displacement of the joint surface is called a Subluxation. Repetitive use of equipment like jackhammers can lead to repetitive strain injuries, such as carpal tunnel syndrome.
Step-by-step explanation:
A partial or incomplete displacement of the joint surface is known as a Subluxation. Dislocations are when the joint surfaces are completely separated, while fractures refer to breaks or cracks in the bones themselves. A repetitive strain injury could be caused by the repeated use of tools like a jackhammer, which can lead to conditions such as carpal tunnel syndrome. Muscle strains are treated with padding to help protect the injured muscle and to provide support while it heals.