I have hEDS and have suffered from severe low back pain, upper back pain, severe neck pain, and saw a lot of chiropractors, massage therapists, and have had a lot of xrays. Often the pain was very sharp, and my back or neck felt "locked".

What has helped me is this:

Stop going to chiropractors and massage therapists.

Using massagers I bought on Amazon (I think I had a lot of overly tight muscles compensating for the weak joints and other muscles that were weak). I bought these and love them: https://www.amazon.com/gp/product/B00BOYA2M2, https://www.amazon.com/gp/product/B01BZOKLOO

I found that massage therapists would massage all muscles equally, even if I asked many times to focus on an area. I didn't need all muscles massaged equally, I needed very specific ones massaged a lot.

Exercises that focus on strengthening the lower back, upper back, and in between the shoulders. Would highly recommend going to physical therapy too. I got a referral from my Geneticist, and my insurance covers it that way. If you don't have access to physical therapy, you can search for posture exercises and back exercises for those with weak joints.

Rolling my neck on a soft foam roller. Specially, I do the "Melt Method" on my neck. I used to do it a couple of times a week, but now I do it every once in a while.

If I keep up the exercises and massage, I have very little pain anymore. I haven't been to a chiro or massage therapist in almost 3 years. I used to go very often.

Someone at work recommended this stand. They use a simple flat keyboard to type. They also recommended this massage pillow for your back.