This is a variation of a popular abs exercise.
Lie down on the floor. Your feet should be bent at the knees and pressed firmly against the floor.
Grasp a ball or a small barbell plate.
Stretch your arms overhead.
As you inhale, arch your back a little, stretching your abs muscles.
Keep your neck stationary.
As you feel the maximum stretch, exhale and lift up the upper part of the torso as if you crunch trying to bring your shoulders to your waist.
Don't move your shoulders.
Reach the maximum contraction of the abs, hold this position for 2-5 seconds and slowly return to the starting position.
Legs, hip, lower back, neck and arms should be stationary.
Don't bring your elbows forward and don't hold your arms behind your head. Thus, it will be easier to do exercise
If the exercise is too easy, you can hold a barbell plate or a dumbbell over your head
To get a better foothold you can place them against the wall or behind a machine.