Many postures are described in the Bible when people prayed. Abraham fell on his face before God, and Moses prayed with outstretched arms. When he got tired Aaron and Hur had to hold up his arms. King Solomon knelt in prayer and Jesus prayed looking up to heaven.
But the way you communicate with God does not require a certain physical position, but it does give expression to the attitude of your heart. Kneeling before god is a visual image of submitting to his authority. One day every knee will bow before the Lord and every tongue will confess that Jesus is Lord, Philippians 2:9-11.
The Lord heard King Solomon when he knelt to ask God to bless the temple and God’s people. Elijah knelt earnestly (that means you are serious about it) when he asked for rain to end Israel’s drought. That prayer was answered as well.
Your earnest prayers: whatever posture you take, are always heard by God.  Remember it took Daniel 21 days to get his prayer answered, the Lord heard him the day he prayed, but the angels and demons were in warfare during that time until the answer manifested. 
Your posture while you are waiting is praise and thanksgiving. It is a demonstration that you are expecting to receive. The Lord likes His Thank You Letters in advance.

Making Room For The Anointing,

Keith and Mary