The shock test is in general specified by an acceleration varying with time. This profile of acceleration can be obtained with various velocity and displacement profiles depending on the initial velocity of the table supporting the specimen, leading theoretically to various types of programme. The motion study during the application of the shock is useful for the choice of the programmer and the test facility which will make it possible to carry out the specification. All shock test facilities are in other respects limited in respect of force, velocity and displacement. The motion study during the application of the shock is useful for the choice of the programmer and the test facility which will make it possible to carry out the specification. Whatever the shape of the shock, perfect rebound leads to the smallest displacement.