bent backward
The antonym for crooked is straight.
An antonym for creased is straight or smooth
The word straight does have an antonym, which is crooked. So perhaps a crooked line is the opposite of a straight line.
forward
a forward roll
The antonym of recoil is advance or move forward.
straight
the opposite of straight is crooked or wavy.
The usual antonym is backward. Others with regard to direction are reverse or rearward.
Work. . forward word
A synonym for straight is unbent.
oval, or straight