A vest (11) for a human body (14) has an air core (36) coupled to a pulsator (12) operable to subject the vest to pulses of air which applies and releases high frequency pressure forces to the body. The pulsator (12) has tow diaphragms (89, 91) connected to an electric de motor (118) with rotary to reciprocating linear motion transmitting mechanisms (116, 117) operable to generate air pulses in an air pulsing chamber (87). The diaphragms (89, 91) also increase the pressure in a manifold chamber (88). A check valve (99) connects the manifold chamber (88) with a pulsing chamber (87) to allow pressurized air to flow from the manifold chamber (88) into the pulsing chamber (87). An air flow control valve (167) in communication with the manifold chamber (88) is used to adjust the pressure of the air in the manifolds and pulsing chambers.