In this article, an adaptive force control scheme for flexible link manipulators is considered. A hybrid position-force control architecture is employed. The control output is composed of a feedforward and a feedback term. The feedforward torque component negates the effects of the underlying rigid arm dynamics along the desired trajectory. The feedback controller structure corresponds to a Proportional Integral Derivative algorithm. The feedback gains are selected in order to place the close-loop error dynamics poles at pre-specified locations. The effects of the environment impedance, joint coordinate versus end-point sensing, and desired closed-loop error dynamics on the transient system response are investigated. The computer implementation of the proposed controller is presented and the effects of sampling time and quantization errors to the system stability are examined. The proposed control scheme is employed in simulation studies on a two link rigid-flexible manipulator.