Abstract: A walker is disclosed. The walker includes a frame, a wheel, a brake selectively positionable in an engaged state, in which the brake resists wheel rotation, or a disengaged state, in which the brake does not resist wheel rotation, a brake actuator configured to place the brake in the engaged state or the disengaged state, a handle, a hand-position sensor configured to provide a first signal responsive to the handle being grasped in a walking grasp and to provide a second signal responsive to the handle being grasped in a standing/sitting grasp, and a processor configured to cause the brake actuator to place the brake in the disengaged state based at least in part on the first signal and to cause the brake actuator to place the brake in the engaged state based at least in part on the second signal. Related devices, systems, and methods are also disclosed.