I like to complain about yoga instructions. Or maybe I just like to complain. But it doesn’t make any sense to me when yoga teachers employ demonstrably false instructions. One that I have heard often lately is to bend from the upper back.
The Idea as presented in a recent class is to prevent compression in the lower back by bending from the upper back. The main problem with this is that there is no bend in the upper spine. The rib cage exists to protect the heart and lungs and as a result its range of motion is limited. The lumbar spine and the cervical spine are designed to bend both backwards and forwards.
All of the spine’s vertebrae have the same basic composition. There is a body of the vertebrae with two transverse processes that extend out to the sides of the bodies. There is a spinous process which extends backwards from the body of each vertebrae (with a couple of exceptions at the top of the spine). Even though the basic bony segments are the same, the way they are aligned is different in different parts of the spine.
When you look at the picture of the thoracic spine above you will notice that the spinous processes of the thoracic vertebrae are bent down to lay directly on top of the spinous process below it. While this arrangement will allow for forward bending it limits all backward bending in this area of the spine.
When you look at the picture of the complete spine, there is a good deal of space between the spinous processes of the vertebrae in both the lumbar and cervical spine. This space allows for the bending of the spine. Though I think this is the wrong way to look at what we are doing in a “backbend”. We are always trying to extend the spine rather than bend it.