Sitting Knee Tuck

Setup
Sit down leaning back on hands with legs straight and raised just off the ground.
Movement Instructions
Bend and raise your knees until they are overtop of your hips, then lower legs back until straight, keeping them off the ground. Repeat.
Comments
Try to keep legs off the ground throughout the exercise, but if needed just touch feet down in between reps. Keep upper body still throughout the exercise, do not lean to help with momentum.