Jellyfish have no spines, but you do!
The presence of spines literally divides the animal kingdom into two distinct parts. Those with spines are vertebrates, and those without are invertebrates. Makes tons of sense.
Singers are vertebrates, and we use our spines in myriad ways to support our bodies while singing, so let's get to know this most important skeletal structure.
In a normal spinal column, there are 33 vertebrae stacked on top of one another. Each vertebrae has a hole in the center through which the spinal cord can pass, and various holes where nerves can exit the spinal cord and go to the body. So the spine is support, but also a conduit for nerve function. Of course, the vertebrae also provide protection for the spinal cord, and injuries to the individual vertebrae can also result in injury to the spinal cord or to the nerves that are branching out at that particular point.
Spinal discs sit between each vertebrae to allow for the absorption of force and for movement. Each disk has a gel-like center surrounded by a tougher outer ring. Over time, these discs can wear down from years of use, and the result can be painful disc herniations where the gel leaks from the center of the disc and pushes outward. We have heard a fair amount in recent years about forward head posture and its consequences for the cervical spine. Because our heads are quite heavy, when we pull our chins too far forward for too long or bend our heads downward for too long, that can put pressure on the discs in the cervical spine, leading to a greater risk of herniation in this area. I have lately been practicing a regular "bobble-head" exercise where I simply move my head around like a bobble-head figurine to find the balance point for my head on top of my spine. This helps me to be aware of where my head is, and where I'm making the muscles in the back of my neck and the discs in my C-spine work too hard.
Our vertebrae are held together by various ligaments that connect one vertebrae to another in a sort of ligamentous chain, and also connect the vertebrae to other structures in the body. These ligaments help the spine keep its shape, but also allow for flexibility and movement. These can also age and lose a bit of flexibility over time.
While the head is pretty much balanced on top of the spine with the spinal cord coming from the center of the head, you can see from the picture above that most of the torso is in front of the spine. That means the spine is also supporting a lot of weight and movement that is somewhat off-center in the body. By that I mean that if I were designing the torso, I would think that putting the viscera, rib cage, arms, and just about every other thing in the torso evenly around the spine would be an easier way to go and would add less stress and strain to the spine. But as it is, everything is in front of the spine. Therefore, keeping our back muscles strong enough to hold everything in place without being pulled down is a good consideration in our work out plans! For singers, keeping our back muscles toned, as much as is possible depending on individual circumstances, can help with breathing, posture, digestion, and even confidence. Likewise, keeping things limber by stretching regularly can also allow for greater ease of movement when on stage or in rehearsal.
Because we are not jellyfish, singers need to pay attention to their spines, and give them a little love now and then. Your singing very well could benefit from good back health!