Aspects of the present disclosure are directed toward apparatuses and methods for rendering haptic environments, such as may be used in rehabilitation. As may be implemented in accordance with one or more embodiments, haptic rehabilitative movement is effected by providing feedback signals characterizing sensed engagement of a user's lower extremity with a crank coupled to a shaft that is driven by a motor, and controlling movement of the crank in response to the feedback signals. Force may be provided by the motor and shaft, by applying control inputs to the motor that cause the motor and crank to render respective haptic environments while engaged with the user's lower extremity, via rotation of the shaft. The haptic environments may include one or both of impedance-based haptic environments and admittance-based haptic environments.