An apparatus for exerting force on a subject tissue includes a linear motor for generating a force according to a predetermined force profile incorporating at least one motion control parameter. The linear motor is directly coupled to a motor output member to drivingly produce linear motion of the motor output member under direction of a motor controller executing the predetermined force profile. A tissue-contacting member is connected to the motor output member for directly proportional linear motion therewith. A load cell provides load cell feedback to the motor controller. The motor controller adjusts the motion of the motor output member responsive to the load cell feedback to substantially conform the motion to the predetermined force profile. The linear motor moves the tissue-contacting member to contact the subject tissue according to the predetermined force profile and responsively initiate a subject reaction to the exerted force.
