Development of a Mobile APP to Promote Physical Activity in Individuals with Knee Osteoarthritis: a "Move for Knee" Study Protocol

In this no-profit, interventional, double-arm, monocentric study, men and women with unilateral or bilateral tibiofemoral KOA according to the American College of Rheumatology criteria for KOA, aged 45 to 70 years, and radiographic findings (Kellgren-Lawrence grade 1-3) referring to the Physical Medicine and Rehabilitation Unit, University of Campania "Luigi Vanvitelli", will be included. In this trial, the patients will be randomized into two groups:

• patients who will use the "Move for Knee" APP (intervention arm);
• patients who will be advised to engage in free physical activity (control arm). Patients will be directed to one of the arms through random sampling with consecutive 1:1 randomization (intervention:control).

The mobile APP called Move Your Knee is divided in 4 sections:

1. Know Your Knee: this first section allows the collection of data entered by patients, useful for understanding their lifestyle habits and daily physical activity level, and information relating to KOA pathology.

At the end of the questionnaire, the algorithm integrated into the APP's computer code will allow the calculation of the patient's presumed level of physical activity. This will then be followed by the assignment of a specific form which includes the exercises and the related execution parameters (i.e. weekly frequency), and useful advice for safely carrying out the exercises to achieve the specific functional objectives. 2. Move Your Knee: in this section, the patient will be able to select the level of difficulty/intensity in performing the physical exercise (the more advanced levels are blocked until the previous objective is achieved).