A knee brace includes a flexible sleeve made of a flexible fabric; a memory device configured to store a reference configuration of the flexible sleeve; a first sensor configured to detect a configuration of the flexible sleeve; and a sleeve tightening mechanism configured to adjust a tightness of the flexible sleeve. A controller is configured to receive an output signal representing, or indicative of, the detected configuration from the first sensor, compare the detected configuration with the reference configuration, and control the sleeve tightening mechanism based on a result of a comparison of the detected configuration of the flexible sleeve and the reference configuration of the flexible sleeve.