Abstract: A wearable device may be configured to detect and alert wearers to improper movements at a body joint based on a comparison of a lateral angle and a bend angle of the body joint and/or based on measurements customized for an individual wearer of the wearable device. For example, a wearable device may determine a bend angle and a corresponding lateral angle of the knee. The wearable device may compare the determined bend angle and lateral angle with stored thresholds customized for the wearer. The wearable device may select a threshold from the stored thresholds with a bend angle that matches the determined bend angle. The wearable device may then determine whether the determined lateral angle matches and/or exceeds one or more lateral angles associated with the bend angle of the threshold. The wearable device may provide feedback responsive to a determination that the threshold was exceeded.