Patellofemoral syndrome (PFS) is the leading cause of persistent knee pain. It typically results in a dull ache in the inner knee area, which worsens with activities such as running, jumping, or climbing stairs, as well as during extended periods of sitting with the knees bent (known as the "theater sign," where pain is felt upon standing up from a chair or theater seat). Mild swelling of the knee may also occur. Ignoring chronic symptoms can lead to muscle weakness, causing the leg to potentially buckle.The syndrome arises from an issue with the movement of the patella over the lower part of the femur. Normally, the quadriceps muscle pulls the kneecap in a direct line over the femur. However, in PFS, the patella deviates toward the outer side of the femur, causing friction and irritation that results in ongoing inflammation and discomfort. Women are more susceptible to PFS than men. Runners with inward-turning knees, flat feet, or an atypically shaped patella are more prone to developing the condition.Initial treatment involves applying ice, taking anti-inflammatory medications like Advil, Motrin, or Aleve, and avoiding activities that exacerbate the knee pain. The goal of treatment and rehabilitation is to ensure a straighter path for the patella during quadriceps contractions. Strengthening the inner part of the quadriceps muscle can help correct the patella's alignment. Low-resistance, high-repetition exercises such as stationary cycling, pool running, or swimming can help maintain fitness. It's important to review training routines and check running shoes for proper fit to prevent recurrence. In some cases, using braces with patellar centering devices may be necessary. Stretching and strengthening exercises targeting the quadriceps and hamstrings are crucial for effective long-term rehabilitation. "Quad sets," which involve contracting the thigh muscles while keeping the legs straight and holding for a count of ten, form the basis of this program. These exercises should be done in sets of ten, 15-20 times daily. Ideally, this will lead to swift recovery and a full return to sports activities.PFS is also known as "housemaid's knee," "secretary's knee," and chondromalacia patella.