●the "wing" muscles straightforwardly under your armpit, called the serratus front.
There is no restriction to the number of push-ups one can do in a day. Many individuals do in excess of 300 push-ups a day. Be that as it may, for a normal individual, even 50 to 100 push-ups ought to be to the point of keeping a decent chest area, if it is done appropriately. You can begin with 20 push-ups, however do not adhere to this number