Bow Pose will help increase flexibility in your strong spine:
- From Downward Facing Dog, bring your knees to the mat and come to lie on your belly. Bend your knees and hold onto the outside edge of your right ankle and then your left.
- Once you have a firm hold of each ankle, try to keep your toes together, either pointing or flexing your feet. Lift your feet up as high as you can and shift your weight forward so you're resting on your naval instead of on your pubic bone.
- Hold for five deep breaths and then slowly release.
If you need more details, check out how to do Bow Pose here.
Source: Laughing River Yoga