Exhale as you roll and massage down the spine, stopping at the bottom of your rib cage. (mindbodygreen.com)
As you stand up, keep your arms in close and bring your elbows up to the bottom of your rib cage, thumbs to shoulders. (womenshealthandfitness.com.au)
Instead of focusing on raising the legs at the hip (as in a normal leg raise), I want you to focus on raising the legs pivoting from the BOTTOM OF YOUR RIB CAGE. (thebestexercises.com)