"lean your head back" is a correct phrase and can be used in written English.
It means to tilt one's head backward. Example: "The doctor instructed the patient to lean his head back and open his mouth wide for the examination."
"When your eyewear prescription is not up to date, you tend to lean your head back to see better," Dr. Isaac says.
This 15-minute shampoo treatment begins when you lean your head back into a machine that looks like a sink at the salon.
You need only lean your head back, and you will float for as long as you want, face in the air.
"Now the trick is lads is to lean your head back, roll then close your eyes groan loudly stick your bat back under your arm then trudge back to the pavilion with your head drooped down like an old sock.
Try not to lean your head back and start moaning.
"When you lean your head back and look down towards the bottom of your eyelids, it's crazy," Erik said.
By Mary Jo Bang [audio style= wnyc" display= mini" caption="Read by the author". url="http://downloads.newyorker.com/mp3/170130_bang_audio.mp3"] The days when you lean your head forward, then pull your head back, to see the sun is only a chrysanthemum, the eye is a white lake with a black boat moored at a particle pier that says what you want back isn't coming.
When gathering your hair into a ponytail, lean and tip your head back.
So next time you're on the road digging "Kind of Blue" or "Bitches Brew" and feel the urge to lean to the side and tilt your head back just so, left arm riding the top of the steering wheel, check yourself in the rear-view -- it's probably the pimp in you.
Lean your head over the bowl.
