Cuff unit for a functional electrical stimulation system

An apparatus for a functional electrical stimulation (FES) system, the apparatus comprising:

• a flexible housing comprising a frame that is releasably mountable on a user, the frame having:
• a first end;
• a second end opposite to the first end;
• a first peripheral member extending from the first end to the second end defining a top side;
• a second peripheral member extending from the first end to the second end substantially parallel to and spaced apart from the first peripheral member defining a bottom side;
• and
• a plurality of panels coupled to the frame and extending between the first peripheral member and the second peripheral member, the plurality of panels being adjustable and spaced apart to define at least one area that is substantially devoid of material, at least one of the panels being initially movable with respect to the frame and subsequently fixed in place for later use by the user;
• a battery module disposed within the frame;
• a stimulation module disposed within the frame;
• and
• control circuitry coupled to the battery module and the stimulation module.