Why Sitting Hurts (and What to Do About It)

Your spine doesn't have one "right" position that it needs to stay in all day. It is made up of multiple segments that allow you to bend, rotate, extend, walk, run, lift, and move through everyday life. If it wasn't supposed to move, it would be one solid bone.

When your spine is in different positions, like sitting, standing, walking, or bending, the amount and distribution of load through your body changes. Your muscles also have to work differently to support you in each position. The important part is that your body has a certain tolerance for these positions and loads.

Think about it like lifting a weight. If you pick up a 10-pound dumbbell, you might be able to hold it for a while without much difficulty. Keep holding it, though, and eventually it starts to feel much harder. The weight didn't suddenly get heavier. You simply reached the limit of what your muscles could comfortably tolerate in that position.

Your back can behave similarly. A position that feels completely fine for 10 minutes may not feel as good after two hours. You may start to notice stiffness, aching, or discomfort that gradually builds the longer you stay there.

Then you stand up and walk around. It might feel stiff or uncomfortable at first, but after a few minutes of moving, your symptoms start to settle down. This pattern is actually very common.

You can even try a simple version of this with your pinky finger. Gently move it backward toward the end of its comfortable range and hold it there. At first, you may barely notice anything. Keep holding it, though, and the same position can gradually become uncomfortable. When you let go and move your finger around again, that discomfort usually starts to settle down.

Your back anatomy is very different from your pinky, but this illustrates an important concept: the amount of time you spend in a position matters.

It all comes down to load and tolerance.

When you walk, exercise, or even shift around in your chair, the forces going through your back are constantly changing. Different muscles are working at different times, and your joints are moving through different positions.

When you sit for a long period, your body is doing much more of the same thing for much longer. Even if it doesn't feel like you're doing anything, your muscles and other tissues are still working to maintain your position. Eventually, the amount of time spent in that position can exceed what your body currently tolerates comfortably. This is one reason why you can have a back that feels completely fine when you're walking around but starts bothering you after an hour at your desk.

It also helps explain why we shouldn't automatically blame "bad posture." There is no single sitting posture that has been shown to be the one cause of low back pain. Research looking at spinal posture and low back pain has found associations in some studies, but the evidence does not support a simple cause-and-effect relationship where one particular posture is damaging your back.²

Instead, think about posture as one part of the overall picture. A position that is comfortable for 10 minutes may become uncomfortable after two hours. And a position that bothers you today may become much easier to tolerate as your capacity improves. In other words, sometimes the easiest way to change how much load your back experiences isn't to find a "better" position and stick to that; it's to change positions entirely.

Movement gives your body a chance to change how a load is distributed.

When you stand up and walk, your joints move, your muscles contract and relax in different patterns, and the loads going through your spine change. Movement also increases blood flow to working tissues and provides your nervous system with constantly changing information about where your body is and how it is moving.

Your spinal discs also respond to loading and unloading. The discs are living tissues that rely heavily on diffusion for the movement of nutrients and waste products.³ Mechanical loading can also cause fluid to move within the disc of your spine.³˒⁴

There is also a sensory component to movement. Your brain is constantly receiving information from your muscles, joints, and other tissues as you move. Changing positions gives your nervous system new information instead of repeatedly exposing it to the same sustained position.

There is even research to back up the idea that simply breaking up prolonged sitting with active breaks or changes in posture can reduce discomfort and, in some cases, back pain.¹

So if you've been sitting for an hour and your back starts to feel stiff, try standing up and walking for five minutes. Go get some water. Walk around the office. Do a few movements that you already know feel good. If you've been given specific exercises by an MSK provider, this can also be a good time to work those into your day. The point is simply to give your body a different input.

If sitting bothers your back, the answer likely isn't to stop sitting altogether. That's a tough ask in the modern world. Most of us have jobs, commutes, meals, travel, or other parts of life that require us to sit. Instead of stopping sitting altogether, you want to vary your positions.

Variety can come to sitting in many different ways. If you tend to lean to the right when you sit, try simply leaning to the left or another position throughout the day. If you've been sitting for two hours, stand up for a few minutes. If you have a standing desk, alternate between sitting and standing every few hours rather than committing to one for an eight-hour day. You can also change where you sit or what you sit on. This is especially important for people who work from home and do most of their work on the couch.

Quick note: The same principle does apply to standing. Standing all day without changing position isn't necessarily better than sitting all day. People can end up with similar issues because then it becomes another sustained position.

To back things up with a little research, a systematic review of workplace studies found that active breaks involving a change in posture may help reduce low back pain and discomfort.¹ Research on sit-stand workstations also found that, in one randomized trial of office workers with chronic low back pain, access to a sit-stand workstation was associated with reductions in reported back pain over three months.⁶

The goal isn't to eliminate every position that causes discomfort. It's to give your body a break and build your ability to tolerate the positions and activities that are part of your life while giving your body some variety along the way.

If sitting consistently brings on your symptoms, especially if the amount of time you can sit has been getting shorter, it may be worth having it assessed by a healthcare professional. An evaluation can help identify what movements and positions reproduce your symptoms, what movements make them better, and how your back responds to different types of loading.

That information can be useful because, unlike what is often popularized online, there isn't one exercise, stretch, chair, or posture that is going to work for everyone.

For many people with low back pain, exercise and progressive rehabilitation are important parts of improving pain and function.⁷

And sometimes it is as simple as learning how to break up your workday so that you're not asking your back to tolerate the same position for four hours at a time. The goal is to help your back tolerate the things you actually need and want to do.

If your back hurts when you sit but feels better when you move, that doesn't automatically mean sitting is "damaging" your spine. It may simply mean that your back currently has a lower tolerance for prolonged sitting than it does for movement.

Instead of worrying about finding the perfect sitting posture, pay attention to how long you can comfortably stay in one position and what happens when you change positions. Try standing up for a few minutes, taking a short walk, or simply changing how you're sitting. If you have the option, alternate between sitting and standing throughout the day.

If those changes aren't enough, an evaluation can help figure out why your back is responding the way it is and what you can do to improve your tolerance.

You don't need to find one perfect position and stay there all day. Your back needs to move, and giving it some variety throughout the day can go a long way toward helping you tolerate the things you actually need to do.