Abstract: Apparatuses for passive muscle loosening and rehabilitation are described. The apparatuses are assigned for patients who suffer from limited range of motion, stiffness, pain, inflammation, and dysfunction caused by muscles that have become tight, hard, stiff, and contracted due to over use, excessive exercise, repetitive motions, and a life time of usage, as well as other users who desire to keep their muscles loose. The operation principle of the apparatus is based on peg pressing during which pegs extend out of corresponding openings in the apparatus housing and put pressure on a desired part of human body, thereby providing muscle loosening in this part of human body. Different embodiments provide different ways of driving the pegs to extend out of the apparatus housing.