With this study two different therapeutic exercise regimens will be compared in patients with anterior knee pain (patellofemoral pain syndrome, PFPS).

Exercise therapy is widely used in the conservative treatment of patellofemoral pain syndrome (PFPS), but there is still no consensus on recommending any specific rehabilitation program.

This study evaluates two different therapeutic exercise regimens in patients with PFPS and their effect on pain at rest and function.

Supervised exercise therapy will be applied in both groups three times a week over a 3-month period with individually tailored and graded exercise programs, differing between groups in terms of number of exercises, number of repetitions and sets, and time spent on performing aerobic exercises.

Inclusion Criteria: Presence of at least 3 symptoms of the following:

Pain when

• Walking stairs
• Squatting
• Running
• Cycling
• Sitting with knees flexed for a prolonged period of time
• Grinding of the patella
• Other positive physical tests (Clarke's test, patellar crepitus, tenderness upon palpation of the posterior surface of the patella, patellar facets or surrounding structures)

Exclusion Criteria:

• Knee osteoarthrosis/ arthritis
• previous knee injury or knee operations
• patellar tendinopathy
• Osgood- Schlatter's disease
• Other defined pathological conditions of the knee