A portable mechatronic rehabilitation system easily adaptable to different situations—e.g., different body members, training modes and physical spaces—using Internet of Things communication and designed applying a methodology based on user requirements, named SARPA, is developed. Bedridden patients, i.e., those who stay in bed for long periods, often have diseases due to immobility. Conventional rehabilitation to mobility recovery is conducted by therapists who present humanly limited strength characteristics (force, speed, etc.), mainly if the patient is overweight. Mechatronic rehabilitation systems aim to optimize comfort, cost, force, and time to the user, i.e., the patient and therapist pair. However, in general, these systems are conceived to execute just one training mode on just one determined body member in the lower or upper limb. Therefore, a different system is often required for a different training mode or body member. Using SARPA, users may select a body member (among lower or upper limb), an active (isokinetic, isotonic, or isometric), or passive mode and configure it according to a specific therapy. SARPA is configured through a Human Machine Interface based on the Internet of Things, with characteristics that may exceed the values of a human-made conventional rehabilitation. The SARPA flexibility allows several rehabilitation options using a single system. Through SARPA, it would be possible to program games or competitions among patients using the Internet of Things technology, improving their mood and autonomy level during therapeutic sessions. In this paper, it is presented the SARPA system design methodology—based on user requirements, construction and preliminary applications in a hospital.