Patellofemoral pain (PFP) is one of the most common problems among physically active individuals between the ages of 15 and 30.
PFP affects 23% of the entire population,  from  young to older adult, and a rate of 17% for all patients presenting knee problem in
general practice. 

Based on current evidence and clinical practice, clinicians are encouraged to offer an individually tailored multimodal
treatment including mainly exercise therapy and education. However, despite the reported benefits of multimodal treatment for PFP,
longer-term follow up data indicates that a large number of individuals with PFP continue to experience symptoms and unfavourable
outcomes. Indeed, the proportion of those reporting chronic symptoms is alarming, from 40% after 1-year follow-up, 57% after 5-8 years
and up to 91% after 18 years. Implications of this poor prognosis are severe, patients with PFP have major limitations of daily
activities, work, and athletic participation and Blønd & Hansen, (1998) reported that 74% of individuals experiencing PFP will
limit or stop sport participation. 
Numerous authors highlight that poor long-term outcomes for the treatment of patient with PFP are explained by several major
factors concerning the implementation of exercise therapy : lack of individualization of the exercises in terms of type, frequency,
intensity, mode, time and rest intervals (1); insufficient duration of the exercise program in weeks (2); patients with poor
adherence and no interest in exercises (3)15. The dose–response association between adherence to exercises and recovery suggests that
adherence is highly important and that the more often exercises are performed, the greater the odds of recovery11. However, the
longer the duration of the intervention the lower the adherence obtained in the individuals that underwent the program. With the aim
of increasing the long-term adherence to physical exercise, it seems that there is a need for alternatives to escape from routine
and avoid interventions that could bore or overwhelm the patients. In this context, the overall objective of the project is to
develop a mobile application and to evaluate its interest for the management of patients with PFP.