Valve actuators include a control system and at least one human-machine interface device. Human-machine interface devices include at least one wireless input device operable by a user and at least one sensor configured to sense a force applied to the at least one wireless input device by the user. Valve systems may include such valve actuators. Methods of operating a control system of a valve actuator include sensing a force applied to at least one wireless input device and wirelessly transmitting an electronic signal in response to the applied force.