A fatigue testing system (100) provides simultaneous cycle testing for a plurality of prosthetic devices under simulated physiological loading conditions. A plurality of sample holders (129) containing test samples (130) of prosthetic devices is positioned between a distribution chamber (126) and a return fluid chamber (136) to form an integrated test chamber (106). A reciprocating linear drive motor (105) operates a rolling bellows diaphragm (115) to cyclically pressurize fluid within the test chamber (106) and drive the pressurized fluid through the prosthetic devices (130) being tested. The test chamber (106) defines a return flow conduit (124) in fluid communication with each of the sample holders (129), the return fluid chamber (136), and the distribution chamber (126). Compliance chambers (135) and throttle valves (132) associated with each of the sample holders (129) regulate the pressure gradient and back pressure across the prosthetic devices (130) being tested.