All movements are possible in each region of the vertebral column, with the range of motion determined by disc thickness and articular process geometry. The movements of flexion, extension and lateral flexion involve compression of the intervertebral discs at one edge and stretching at the other.
It is important to note that rawhide bones and chews made in USA are the absolute best for your dog. Choosing American Rawhide, Merrick, Dingo, Bone Buddies or Beafeaters brands you give your pet a rawhide chew of premium beefhide from corn-fed American cattle produced under the strictest quality standards. American production processes and sanitation practices are much better and more highly regulated than most other countries producing rawhide bones.
Re: Swallowed chunk of rawhide. In all honesty you need to contact your vet. Rawhides do cause blockages, especially in smaller dogs, because the pieces are too large to pass through the intestine. Contact your vet, and ask for some x rays. Cheapest, and most effiecient way to see if there is a blockage, how large the piece is, and if it is moving through.