What causes back aches?

The muscles along the spine pull in different directions and when you strain of pull one of the muscles in a certain direction the muscles on the opposite side pull in the opposite direction so that your spine stays straight.
Sitting up straight should not cause you to have pain unless you are flexing your back muscles in which case you probably just need a break.

Is that your mouse arm? Do you change positions frequently? You should.

As one ages, the back has to work harder. The spinal cord, the vertebrae, the nerves, the fascia, and all the other soft tissue need to be loved and supported.

Get some suitable core strengthening and stretching exercises, designed for your particular back.

Use supports.. a rolled-up towel or magazine, a small cushion in the small of your back does wonders. Chairs with no backs make your back work harder.

I have chronic back trouble;

What I do;

Sleep on a hard mattress on my side.
Drive with a lumbar support
Do stretches and weigh-bearing exercises every other day.
Stand up straight and hold belly in whenever possible.
Improvise; when at a restaurant or the movies, say, and the seat is uncomfortable, I will bunch up part of my jacket and stick it behind my back.

I have twi ergonomic chairs (expensive but will outlive me) for my computer station and my real-paper desk area.

I never sit anywhere without a little forethought.

Eternal vigilance and sucking it up pay off.

Several years ago I had a shoulder problem that caused a lot of pain and reduced range of motion. It felt like what I’ve read about a rotator cuff injury in athletes. (I’m not an athlete.) I couldn’t imagine what the problem was, since I had done nothing to “injure” the shoulder.

It got so bad that I saw a doctor, had an xray taken, and had physical therapy for the first time in my life. While in PT, and after interviewing about my activities and having the pain / range of motion limits checked, the therapist came to the conclusion that it was all posture-related. That is, as a computer user I often sat somewhat “hunched” over the keyboard or laptop, and that sloping forward of my shoulders caused the problem and worsened it.

At first I didn’t believe them, but the PT and exercises I was doing seemed to make the problem go away. So I was happy for that, but as soon as one shoulder was fixed, the other one started to have the same problems! So I continued the PT on my own, more or less, and this time I made note of my posture: I sit straighter, I sit back more (with support), and I make a conscious effort to square my shoulders and back when I walk.

It makes a difference. My back and shoulders feel fine now.

PS: I also changed my laptop computer bag from an “over the shoulder, single strap” briefcase type, to a two-strap backpack that I always wear square on my back. It might look dorky, but that probably helps as much as anything. I watch people walk into work leaning to one side against the weight of a computer bag (no matter how they carry it in one hand or off one shoulder) and I know that they’ll be having problems too someday, if they don’t already.

If you believe in mans past history, we were not supposed to walk on two legs.

I can give my lifes history, concering backs, in this answer.

The back muscles, especially the lower back, have a load to carry with the human body. If these muscles are not in good shape, they will go into a frenzy with muscle spasms, at the first amount of stress imposed upon them.

Back pain is No.2 in human complaints to doctors.

I was in a police motorcycle accident in 1971. I was in a year of pure torture with two lower lumbar discs bulging in toward my stomach. I held off surgery for as long as I could. In 1972, I I had my first back surgery at Vanderbilt Hospital. In 1972, there was no endoscopy. The surgeon had to cut the back muscles on the right side of my spine, in order to reach the effected discs. I recovered from this surgery, but had three more back surgeries, because of this initial surgery. A space had been left in my spine and like dominoes, two more vertabraes collapsed.

I made it pretty good for the following years, until I had to have neck surgery. A piece of my hip bone was taken to place in my neck and a stabilizer plate was installed. I recovered from this surgery, but still have complications from my hip. Sooooooo….............

Now, scar tissue has taken over the right side of my spine and into my lower spine. There is no procedure for this, other than a spinal injection. I have had three sets of injections, so far, and the last set accomplished nothing. So. the bottom line here looks like pain pills and muscle relaxers for the rest of my life.

I did not mean to tell my backs life history, but you did ask the question.

In conclusion, take care of your back and keep it strong. A hurt back will cause your whole body to be involved and your life willl be forever changed.