After knee arthroplasty rehabilitation is fundamental to patient's functional recovery, but in recent years there has been a growing interest in the possibility to prepare patients for surgery through a prehabilitation program. This two-parallel groups randomized clinical trial aims at evaluating the effects of a preoperative rehabilitation programme carried out at patient's home using advanced technologies, on subjects waiting for knee replacement. In particular, the primary objective of this study is to assess the superiority of a tele-prehabilitation programme compared to standard prehabilitation (remotely delivered with a booklet) in determining an improvement in lower limb function, as measured by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire, at the end of the programme. This study also aims at assessing possible differences between groups in muscle function, pain, autonomy in the activity of daily living, adherence to treatment and patients' satisfaction with the prehabilitation modality. Through the analysis of quadriceps muscle and blood samples, we will also evaluate possible changes in the expression of specific markers that the prehabilitation programme may be able to determine at muscle level. Both the intervention and the control groups will perform a prehabilitation program in the 6 weeks just before surgery. The program will include therapeutic exercises and educational contents. Subjects in the tele-prehabilitation group will receive a tablet with two accelerometers and a balance board for the remote execution of the program, while the control group will receive the same intervention through a booklet. Subjects recruited will be assessed at 5 timepoints: before starting the prehabilitation program, the day of surgery, 7± 2 and 15 ± 2 days after surgery, 3 months ± 7 days after surgery.