satipatthana

keeping the object in view
The function of sati is the absence of confusion,or non-forgetfulness(asammosa rasa).This means that the nothing and observing mind should neither lose sight of,nor miss,nor forget,nor allow the object of observation to disappear. To express this aspect positively, the function of sati is to keep the object always in view. Just as a footballer never loses sight of the football, a badmintom player the shuttlecock and a boxer his opponent`s movements,so too the yogi never loses sight of the object of minfulness.
Confrontation and protection
There are two manifestations of sati,namely:coming face to face with the object; and protection.

Face-to-face with the object
The chief manifestation of sati is confrontation-it sets the mind directly,face-to-face,with the object of observation(visayabhimukha bhava paccupatthana). Sati manifests as the mind in a state (bhava) with as object or objective field(Visaya).

It is said that the human face is the index of character. Therefore,if you want to size up a person, you have to be face-to-face with that person and examine his or her face carefully.Then your judgement will be correct.But if you stand at an angle, behind or far away from that other person,then you will not be able to distinguish the distinctive features of his face.
Similarly, when you are observing the rising movement of your abdomen,if the mind is really face-to-face with the rising movement,you will notice different sensations in the rising such as tention, pressure,heat,coolness or movement.