Osteoarthritis (OA) is a common musculoskeletal disease that appears along with degenerative changes in the synovial joints and new bone formation [
1]. It is the most common form of arthritis and joint disorder that adversely affects the public health [
2,
3] and is the main known cause of disability. Recent estimations show that over 240 million people worldwide are suffering from this debilitating disease [
4]. OA is commonly seen in pelvic, knees, spine, and finger joints[
5]. However, knee OA is the most prevalent OA (33% prevalence) and has more clinical symptoms than any other forms of OA [
6]. It is one of the five causes of disability in the elderly [
7,
8]. In the United States, 14 million people are affected and more than half of them are under 65 [
9]. American studies show that OA is on the rise [
10]. Similarly, the prevalence of osteoarthritis seems to be increasing in Iran.
In epidemiological studies, including Community Oriented Program for Control of Rheumatic Diseases (COPCORD) the worldwide prevalence of knee osteoarthritis has been estimated 7%. The prevalence of OA in Iranian population over 15 years old has been estimated to be 16.9% and that of knee OA 15.5%. Regarding the prevalence of knee OA, Iran is ranked third among the studied countries[
11,
12]. Osteoarthritis reduces mobility, quality of life, and well-being [
13,
14], and increases health care and economic burden [
15]. Unfortunately, the growing elderly population, sedentary lifestyle and obesity can add to the complications and the prevalence of OA. The prevalence of chronic osteoarthritis is predicted to increase and become the most common chronic skeletal disease in 2040 [
16]. Aside from bone and joint damages, OA appears as a result of degeneration and destruction of the articular cartilage. It is usually seen in people over 40 and has slow progression rate as a result of repeated natural or abnormal pressures [
17]. Knee osteoarthritis is caused by the incorrect performance of daily activities at younger age, as well as improper lifestyle and bodily movements [
18]. Women account for a higher percentage of the OA patients [
19] and female sex is a risk factor that increases the likelihood of developing OA [
20]. Women experience greater incidence and more severity of OA than men, so it is necessary a greater need for effective treatment and prevention of OA in women[
21,
22]. In addition, women often illustrate greater pain and more substantial reduction in function than men, which can lead to sarcopenia [
23]. Lower extremity muscle appears to play a greater role in the development of knee OA in women than in men[
24]. Although, the prevalence of OA is high, the population mean age is growing, and OA effects on mental and physical health [
20], there are currently no methods to cure or stop the cartilage destruction [
25]. Available treatment options are limited and at best can be effective on some patients [
16]. The person with OA lives with it for 26 years on average [
26,
27] and carries the burden of the disease for a long time. Not only the medical treatments, but also systematic health care is essential for proper treatment of OA [
20]. Therefore, early diagnosis and continuous monitoring of OA progress are important in establishing effective treatment [
28]. OA treatment goals include relieving pain and inflammation, lowering stiffness, improving function or range of motion, and improving or maintaining the mobility, physical activity, and health-related quality of life [
29]. To achieve the treatment goals Patient education is needed. This is a continuous process and an integral part of patient management. The trainer should consider different aspects of the disease and the benefits and risks of treatment options. Empowering the patients by involving them in the decision-making process and teaching them skills for positive changes in life is a lengthy process for treatment [
30]. This makes the individuals tired and may cause them to forget parts of their trainings. Therefore, patient education requires consistent monitoring of the patients’ performance. Due to decreased mobility and increased disability, the patient may not be able to visit the trainers in person and receive ongoing monitoring. Some believe that the available web-based approaches are more comfortable for the patients and can help them cope with the current shortage of skilled professionals and obstacles to ongoing face to face monitoring [
12]. Dallimore et al. reports that the patients who used iPad scored significantly better in terms of recovery indices and were more satisfied with their treatment than other patients [
31]. It has been also found that using technology tailored to users' needs lead to continued training in patients with OA and improve the motivational and behavioral factors [
32]. A study has shown that the use of pedometer to provide feedback on walking activities of OA patients contributes to the attainment of OA treatment goals [
33]. Another study found the use of smartphone app to be effective in training the OA patients and improving their condition [
34].
Today, cell phones are part of everyday life, including health services. Mobile apps have the potentials to be exploited for medical purposes like instructing the patients for preventing diseases. In addition, the use of mobile apps can help for timely diagnosis and treatment, and lowering the costs of medical cares. Therefore, we decided to design a mobile app-based training program for patients with knee OA and evaluate its effectiveness on physical performance and behavioral change of these patients. Designing such apps allows for better monitoring and consistent instruction because it saves time and money, and frees the patients from the troubles of visiting their doctors in person. Proper and timely education can improve the quality of life in OA patients and reduce the incidence of knee osteoarthritis and its complications.