A prosthetic device comprises a connecting portion for connecting to a person using vacuum; and a control structure for controlling an amount of vacuum used to connect the connecting portion to the person, wherein the control structure includes: a vacuum pump (502) in fluid communication with the connecting portion for controlling an amount of vacuum used to connect the connecting portion to the person, a vacuum sensing mechanism (506) configured to provide signals indicating the amount of vacuum in the connecting portion, a movement sensing mechanism (509) configured to provide signals indicating at least one of acceleration of the prosthetic device, orientation of the prosthetic device, force experienced by the prosthetic device, and a direction of force experienced by the prosthetic device, and a controller configured to receive signals from the vacuum sensing mechanism (506) and the movement sensing mechanism (509), and to control the vacuum pump (502).