A prosthetic device for attachment to a residual limb is provided that includes a socket-forming member configured to receive the residual limb, a first portion, and a second portion that is operatively connected to the first portion and rotationally movable relative to the first portion. The prosthetic device also includes a pump attached to the first portion that is adapted to draw a negative pressure within the socket-forming member upon rotational movement of the second portion relative to the first portion.