Lie on your back, spread your arms to your sides for a wide base, and lift your straight legs into a vertical position. Slowly rotate the trunk to bring your legs to the floor on one side, then back to the other side.
 
Purpose
The floor wiper is a more accessible variation of the windshield wiper for training trunk rotation without the added demand of the isometric trunk support in a hanging position.
 
Programming
Sets to maximal reps (not to actual failure) or of 10-20 each direction are typical.
 
Variations
The motion can be slowed down or the feet not allowed to touch the floor to increase difficulty. Weights (dumbbells/kettlebells, barbell, etc.) can be held in straight arms above the chest during the exercise.