BOWING DOWN ONLY AN ACT OF WORSHIP ?

have heard many Muslim argue bowing down face on ground is the only acts of worship .

if Muslim doesn't understood what worship is, they won't ignorantly says bowing fell one face on ground is the only an act of worship , how true is their claims ?. many of them run quickly to quote some biblical verses to justify there claim , if bowing and felling one face on ground is the only an act of worship , then should we by Muslim definition says human bowing to another with face on ground is worshiping of human like them ?

1 SAMUEL 24:8: “Then David went out of the cave and called out to Saul, ‘My Lord and king!’ When Saul looked behind him, David bowed down and prostrated himself with his face to the ground.”

according to Muslim, David Allah prophet worship Saul ,since bowing down face on ground is the only acts of worship .

1 King 1:22f: “While she was still speaking with the king, Nathan the prophet arrived. And they told the king, ‘Nathan the prophetis here.’ So he went before the king and bowed with his face to the ground.” (This is Nathan, the prophet, bowing to King David! How inappropriate!).

question for the Muslim , since u people argued that bowing facing ground is the only act of worship , what happen to those that are not in position of doing so ? due to their health or physically change ? .

worship is define : as reference to deities .it can be seating , jumping kneeling, praying , singing , dancing felling one face to ground , looking up to heaven e.t.c , anything u do as reference to God is worship .

ITS A SERIOUS MATTER .