Patellofemoral syndrome (runner’s knee) refers to pain arising from the joint between the kneecap and the underlying thigh bone (Fenur). It is the most frequently encountered problem in sports medicine clinics.
CAUSE
Runner’s knee most often results from overuse of the knee. When the knee is bent and straightened, the kneecap slides up and down within a groove on the end of the thigh bone. With repeated bending and straightening such as walking, cycling, running and jumping, the underneath surface of the kneecap can become irritated due to compressive or shearing forces. Apart from overuse, pain and dysfunction can also results from either abnormal forces caused by an increased pull of the lateral front thigh muscle (quadricep) leading to malalignment of the kneecap in its groove.
SYMPTOMS
The main sensation associated with runner’s knee is pain over the front of the knee. This is felt behind and around the kneecap, sometimes associated with grinding noises heard when the knee is bent or straightened, a sensation of the knee giving way and weakness in the knee. Specific populations at high risk of developing this problem is 
runners, basketball players, young athletes and females as well as patients with genu valgus (knock knees). Pain which is exacerbated by sports, walking or stair climbing. Descending stairs may be worse than ascending. Unless there is an underlying pathology in the knee, swelling is usually mild to zero.
TREATMENT
Physiotherapy will include Ultrasound, Cold Laser Therapy, Interferential Therapy, eccentric loading and strengthening exercises, stretches, dry needling and biomechanical corrections. These corrections might include inner soles for your shoes, taping of the knee and posture correction.