Abstract: An exercising device of the type designed to cause movements of predetermined, designated limb portions about a predetermined joint wherein first and second brace assemblies are designed to be mounted in at least partially gripping relation to limb portions on opposite sides of designated joints. A driving means including a drive motor and gear assembly drives an action arm in a substantially reciprocal path of travel so as to cause selected movement of one brace assembly relative to the other brace assembly about a predetermined joint without the patient exercising muscle control or coordination. A control assembly as well as the drive motor and gear assembly are housed as a contained unit and removably mounted on one of the brace assemblies in such a manner as to be movable therewith so as to allow ambulatory movement of the patient during the exercising period.