Phobia is a common term to describe fear of something. Kinesio is used to describe movement. So a person with kinesiophobia is afraid to move. That sounds rather extreme and most people with kinesiophobia are not zombies who walk and move like Frankenstein.
They are often people with chronic pain from an injury. Fear of pain or reinjury makes them very cautious in their movements. They start to avoid anything that makes the pain worse. In the end they may even make the pain worse by using this strategy. The body is designed for movement. Motion is lotion.
Loss of motion tends to make us stiff and feeds into the pain cycle. If the problem goes too far a physical therapist may be needed to help the patient break out of this movement phobia.