A reference to continuous involuntary movements as seen in a disease of the central nervous system: "The hyperpraxic patient told the doctor that something was forcing him to clench his hands and he couldn't stop whatever was causing it."

"The doctor explained that the man's hyperpraxic condition could be a result of a lack of calcium which helps to sustain cardiac muscle contraction because all of the muscles require calcium to work properly. Low calcium also explains the patient's twitching hands because without enough calcium, skeletal muscles can go into spasms."