if left chest pain then what will do?!

Pinched muscles in your back will cause the chest pain for the back muscles often send the pains around your body on the nerves to become pains in the rib, chest or heart areas. Freeing up your back muscles should get rid of this pain for you and here's how to do that:
Back:
(do from a sitting position)
Place your left hand on your left leg next to your body. Place your right hand over your left shoulder, fingers over the back and the palm in the front and firmly pull down on them and hold. After 30 seconds slowly lower your body forward and to the outside of your left leg, keeping your left arm fairly straight as you do. When you reach your lap remain there for another 10 seconds, release the pressure but rest there for another 30 seconds. Then reverse your hand positions and do your right side.
For best results relax your body first by taking a deep breath and exhaling then remain this relaxed.