Starting the downswing

All good golf swings start the downswing from the ground up. The movement starts with the feet then knees followed by the hips. This movement allows the arms and club to lower into the slot.
Moving the lower body forward and then turning through helps delay the uncocking of the wrists and holds the clubface open until just before impact. By making this motion all the energy of the swing is moving in the correct direction and helps create more force at impact by hitting into the left side.
You see this motion repeated time again when watching the golf telecasts on all the Professional Golf Tours.