Happyloser points out factual and relevant information.
As we age there is a gradual loss of fluid in the discs in the spine. This reduces space between the vertebrae and puts more pressure on the joints.
As you can imagine, CNA work is often hard labor. Twisting, turning, bending, reaching, pulling, lifting, .... all of this puts stress on your body. Proper lifting techniques won't be worth a darn if there is an underlying condition which becomes activated with all this laborious work.
I worked as a CNA in my early 20's at a long term care facility. I would often have to lift, transfer, pull, and turn heavy patients on my own when no one else was available. In those days I would have an occasional lower back pain after my shift but it would always go away after a good nights rest.
After graduating college I've decided that I'd like to get back into the nursing field. So I took a hospital nurse aide job while getting my pre-reqs for nursing school. I've been at the hospital for about two years but am currently on a medical leave...
I developed sciatica in one leg but I kept working thinking that I just needed more exercise, etc... Once my toes started getting numb I decided to see a spine specialist. I have a herniated lumbar disc. No idea when it happened as it's possible to have a herniation without any symptoms.
I've been through three rounds of lumbar epidural steroid injections and one round of injections in the facet joints (spine joints) and sacroiliac joint. Along with a lot of physical therapy and various appointments with other specialists.
I'm certain that I had these problems prior to my most recent patient care position. It's just that all the heavy labor of the job aggrevated my underlying condition.
I'm not sure if I will be returning to my job even if/when I do get into physically acceptable condition. I really don't like having to put my physical health on the line in order to care for ten-twelve patients a shift. And when it comes to helping a patient who is about to fall to the floor...what can I do? Injure myself while helping to break the patients fall or keep myself healty and just stand back and watch them fall????
And from my experience, quite a few of the patients are able to push themselves up in bed, sit at the side of bed, and stand but they prefer the nurse aide to lift them out of the chair, pull them up, etc...Maybe these folks enjoy watching us break our backs???