Nordic leg curls

Kneel on a padded surface and keep your body completely upright.
Either have someone hold on to your ankles, or place them below a sturdy object to ensure stability.
Cross your arms, flex your core, and make sure your hips are aligned straight with your body.
Breathe in an lower your body forward by only extending from your knees and resist as much as you can from falling down to the floor.
If you can pause at the bottom and go back up without assistance, breathe out and lift yourself back to the starting position.
If you cannot pause and go back up without assistance, breathe out and catch yourself with your hands at the bottom and push yourself up to the starting position.