Abstract: A joint excursion monitor device which, when strapped onto a person's leg, can monitor a pre-set limit of joint movement, and when that pre-set limit is reached, generate a signal. When set to a point just beyond the allowable limit, this signal may be used to alert the wearer that he has exceeded the allowable range. Alternatively, when set to a point just inside the allowable limit, this signal may alert the wearer that the desired goal has been reached. The device may also count the total number of joint excursions. An alternate embodiment additionally monitors a second plane of joint motion, generally perpendicular to the first plane of motion, and similarly initiates an alarm signal in the event that the wearer should exceed a pre-set allowance.