Motor with freewheeling, variable friction and force exertion
I believe that the performance that you describe requires a servo motor with a high resolution shaft position feedback to a high quality controller. In order to select a torque rating, you need to quantify "force so that a human can not hold the shaft" and also define the maximum speed for shaft rotation under motor power. A servo motor system can hold a shaft at a fixed position quite well, but not as solidly locked as a friction brake.