Hello, in order to do for example the hundreds, we are asked to lift our head up off the mat. our shoulders lift a bit as well but our shoulder blades don't. my tummy is not strong enough for me to do this and my neck hurts too much. how can I modify? or what can I do?

You can place a small inflatable ball (approx. 8" in dia.) under your head, ensuring it is on the skull not under the neck, and nod your chin towards your chest. You could also place the ball under your bra-line in back to get your head and shoulders higher, but this is a little more demanding on the abdominals. Alternatively, you can place one hand behind the head and pump with the other, and then switch hands halfway through. Be sure not to pull on your head with your hand, but instead make a "wall" with your hand for your head to lean against. Also guard against rotating or side-bending the torso, a tendency when the arms are in different positions like this. In any of the positions, draw your shoulders down from your ears and your abs in as you exhale. Hope this helps!

Selcan ~ This video on Chest Lift Modifications might be useful to figure out ways to build strength in a safe way. I hope this helps!