A vibration apparatus (8) for use on therapy and exercise equipment of the type that has one adjustable, hanging rope or a pair of adjustable, hanging ropes (5; 6) to which is attached a grip portion, sling or other support member (3; 4) for an equipment user (1), the vibration apparatus being designed to be attached to the rope or to extend between the ropes and controllably set the rope or ropes in vibration. The vibration apparatus is freely, but fixably mountable at any level along the hanging length of the rope or ropes by means of rope gripping members (9; 10) on the apparatus or at respective ends of the apparatus, and the vibration apparatus has an actuator, for example, in the form of at least one electrically controllable motor (11; 12; 13) that cooperates with at least one weight (H'; 11"; 12'; 12"; 13'; 13") that is eccentrically supported in relation to the rotational axis of the motor.