Thank you all again for your prayers and well wishes.

Yes Debbie, you are right, it is, thankfully, a sprained muscle and he should back to himself in a few days. Hopefully there will not be a repeat of this, but if so, I won't be such a basket case like I was last night.
The vet did a very thorough examination of his back, legs and paws and dear sweet Poppy was purring away while clinging onto me. What I love about him is that when the vet is finished doing what he has to do with him, Poppy will reach up to me to be picked up and wraps his paws around my neck. This is the ONLY time he does this and it just melts my heart.
He is 8 months old now and weighs 10 lbs.

Here is what my silly little clumsy monkey is doing right now.
Going to the vets is soooo tiring.