An impairment in the performance of voluntary actions despite intact motor power and coordination, sensation and perception, and comprehension. The apraxic person knows the act to be carried out, and has the requisite sensory-motor capacities; yet performance is defective. The abnormality is highlighted when the act must be performed on demand and out of context. The individual may perform normally in such activities as hammering or tooth brushing performed with the object in hand, especially in a natural situation, but will often fail when required to pantomime such acts.