Background: Various methods and means are available for patients in rehabilitation after arthroplasty of the knee with total endoprosthesis, including the use of devices with biofeedback, thanks to which the patient learns conscious control of the given activity in a way adequate to the information received. Therapy with biofeedback is especially effective for individuals for whom pathological afferentation occurs, as a result of the ensuing pathological process affecting the limb.
Material/Methods: 18 patients following arthroplasty of the knee with total endoprosthesis due to degenerative changes were qualified for participation. The patients were divided into two groups depending on the time that had elapsed after surgery before rehabilitation was commenced. The tests were conducted twice, once before and once after the cycle of physiotherapy procedures.
Results: The measurement of the scope of active movements conducted in the first examination showed small differences between the two groups. Times were also analysed: the total time of exercise, time in the marked field, and time outside of it. In group 1 all the average values for these parameters were greater than in group 2.
Conclusions: Commencement of the rehabilitation program within a few weeks after arthroplastry of the knee with total endoprosthesis brought better results than in the case of patients who entered rehabilitation 3 months after surgery.

Keywords: Exercise Therapy - methods, Biofeedback, Psychology - methods, Arthroplasty, Replacement, Knee - rehabilitation, Knee Prosthesis