Abstract: A hand held massage unit used for therapeutic purposes such as to loosen and mobilize bronchial secretions in patients, to improve blood circulation, and to relax muscles. The massage unit includes a vibration-free motor unit having a rotating output shaft directly connected to a vibratory head assembly. The rotational motion of the output shaft is transformed into oscillating orbital motion about the shaft centerline in the adapter portion of the vibratory head assembly by means of an offset cam integrally formed as part of a counterbalanced eccentric. Counterweights within the eccentric reduce the vibrations transmitted to the user's hand and isolate the oscillating vibration of the vibratory head assembly. Undesired rotation of the vibratory head assembly is prevented by a mounting construction between the oscillating adapter components and a stationary portion of the vibratory head assembly secured to the motor unit.