While performing this movement, make sure the leg that is in contact with the floor to be straight in line from hip down to the ankle. With the leg on the door frame, find a passive stretch that can be help for 1-2 minutes. After the passive stretch has been held, perform PAILS & RAILS. Consider pushing into the wall, contracting the hamstring and glute against the wall providing feedback. The inverse, would be to contract your quadricep and hip flexor to lift your leg off of the wall to gather more range of motion at your disposal.