What should be done with patellofemoral syndrome, with hamstring stretched or strengthen? I believe that as IT band is tighten, it should be stretched.

The majority of exercise programs intended to treat Patellofemoral pain syndrome (PFPS) are designed to strengthen the quadriceps muscles. Emphasis during exercise may be placed on coordinated contraction of the medial and lateral parts of the quadriceps as well as of the hip adductor, hip abductor and gluteal muscles. Many exercise programs include stretches designed to improve lower limb flexibility.

Electromyographic biofeedback can also be used for treatment and allows visualization of specific muscle contractions and may help individuals performing the exercises to target the intended muscles during the exercise. Electrostimulation may be used to apply external stimuli resulting in contraction of specific muscles.

A 2011 systematic review stated that evidence supports the use of quadriceps exercise for managing patellofemoral pain syndrome and that quadriceps strengthening is considered to be the “gold” standard treatment for patellofemoral pain syndrome.

Reference 1: Bolgla, LA; Boling, MC (2011). An update for the conservative management of patellofemoral pain syndrome: A systematic review of the literature from 2000 to 2010. International Journal of Sports Physical Therapy 6 (2): 112–25.