Spinal flex / ext 1 (Trunk/spinal flexion stretch series 1) Round 2) Sit back 3) Return 4) Neutral, in quadruped; 01)

This exercise has four parts, starting on your hands and knees.
Part 1: Inhale, as you roll your spine up, tucking your tail bone under, curling your back up by pulling your abdominal muscles in, and tucking your head down.
Part 2: Exhale, as you gradually sit back on your heels.
Part 3: Inhale, and push from the shin into the floor to come back up onto all fours. Keep your spine C-shaped throughout this phase, with your had and tail bone tucked in, and abdominal muscles engaged.
Part 4: Exhale, as you soften the arch in your back, lifting your head back to neutral spine and finding length through your back.