Most of the Bible prayers are short prayers, the Lord's pattern-prayer is one of the shortest.

It is the heathen who think they will be heard for their much speaking.

Nehemiah's was a true prayer, and an answered prayer, yet it was but a moment in length.
Nor are uttered words necessary to prayer.

The followers of Baal cried aloud, thinking their much shouting would reach the ear of their god, but Nehemiah speaks not, does not even whisper, and his prayer is heard in heaven.

Surely now-a-days, when there are some who seem to think that much noise, that loud shouting, that the uplifted voice must needs pierce the sky, it is well for us to be reminded that God heeds no language, hears no voice, but the language of the soul, the voice of the innermost heart.
Nor is posture a necessary part of prayer.