You need to work your abs to stabilize your low back while criss-crossing your legs, which also works your inner thighs.
- Lie on your back and place your hands under your pelvis with your palms on the floor to help protect your lower back.
- Pull your abs to your spine and round your low back, then lift your legs up to a 45-degree angle. Cross your right leg over your left, then switch. Keep your low spine pushing in to your hands as you continue criss-crossing your legs for 30 seconds.