As I've stated before, when our body is weak and/or compromised, so is our voice. Two fundamental elements of vocal strength, namely postural alignment and deep diaphragmatic breathing, are often stymied by whatever other physical conditions are going on. Chronic pain and tension can, over time, weaken our voice considerably if we're holding our body in a position that is not what it should be, causing intense misalignment of the spine. Pain can also steal some of our precious breath, if we're breathing "around the pain", and not allowing a full inhale and exhale to take place. In my 25 years of teaching singing and public speaking, I have observed that there is one particular kind of body issue that can sabotage the voice, and that is neck tension.
Take a minute and put your hands around your neck. See if you can touch your thumbs and index fingers together. If you can then you have a smaller-sized neck, but even if you can't the neck circumference is actually quite small, compared to the enormous job it has to do. Crammed inside that area is your spinal cord, your esophagus (where the food goes down), your trachea (windpipe), on top of which sits your larynx, which houses your vocal cords. As if that's not enough, you also have a series of glands, lymph nodes, and veins, including the vital carotid artery. In addition, the neck contains a series of small but mighty muscles that are used for everything from swallowing to just holding up your head!
It's no wonder that head/neck alignment are so important to the voice. If we are tense in the neck, our larynx can become mis-aligned from its precise position, causing the vocal cords to over-compensate and strain when we sing or speak. Although our vocal cords can "borrow" from other muscles nearby (in a process called "extra muscle recruitment"), this action is not sustainable in the long term, and can cause strain, hoarseness, or even full laryngitis.
There are many causes of chronic neck tension, and you should consult your doctor* if you suffer from it. That said, a few things that you can try for relief include changing to a thinner pillow, working out regularly to build more muscle in the back and neck, making sure that your work desk is ergonomically aligned, and gentle yoga. One of my favorite things to do at the end of the day is to stand with my back to a wall, and roll around on this therapy ball, which is soft enough to be gentle, but firm enough to loosen tight muscles in the shoulders and neck. Try it gently at first, for 60 seconds on each side of the spine, and see how it feels.
Once you've freed up some space in your neck, your voice should feel more relaxed, full, and free. Everything we do with our voice should have these qualities.
NOTE: consult your doctor before trying any of the neck tension relief methods listed in this post.