Supine knees side to side (Lower trunk rotation AROM, arms out to side, supine feet standing)

Lie on your back with your knees bent and your feet flat on the floor.
Extend your arms out to the sides and keep your shoulders on the mat at all times.
Keeping your knees together, drop them down to one side, rotating your torso.
Return to the starting position and allow your knees to fall to the opposite side.
Only drop your knees as far as you go comfortably.
Hold the stretch on each side if you are able to.