According to a first embodiment of our invention, a monitoring device is placed above, within, or on the bottom of a cast, boot, shoe, or other lower extremity immobilization or protective device, and has one or more single or cluster of pressure sensitive chambers designed to burst at a predetermined force or weight. The pressure sensitive chambers may be filled with air, liquid, semi-liquid, or particulate material. Once properly positioned, the device serves to detect and alert one or more individuals to the fact that weight-bearing has occurred and/or that a certain amount of force has been transmitted across the bottom or other portion of the cast, boot, shoe, mat, sock, insole, or lower extremity immobilization or protective device in a setting where such pressure could be deleterious or harmful (including situations where patients are recovering from a bony fracture, tendon injury, and recent lower extremity surgery).