You need a wide enough array of movements the same way a diet has to be made out of a wide enough variety of foods to cover all your nutritional needs. We have lost variety when it comes to movement.
Even when people are trying to fix these issues, they do so with a very limited monotonous solution. Like running on the treadmill for an hour or replacing sitting with standing.
Running and standing might be healthy, but that would be the equivalent of a healthy diet made out of just apples.
The opposite of sitting is moving not standing, if you just replace sitting with standing what is going to happen is that you're legs are going to hurt you at the end of the day instead of your back. So you just replaced your low back pain wit leg pain.
If you are like most people you spend about 13 hours out of 16 hours of being awake sitting on a chair. The key is to replace some of that time sitting with other forms of movements, plural. Frequency and variety is important. There is no position or activity you can hold or maintain for 13 hours and be healthy.
If you stand for 13 hours your legs are going to hurt, if you lay for 13 hours you are going to get bed sores etc.
For example if you have an office job, you probably spend close to eight hours sitting at your desk, maybe with some short breaks.
You can add some movement variety and still do your work, you can do part of your work standing by elevating your computer so you can use it comfortably while you stand, than you can move your laptop on a chair and squat in front of it, and if you get tired of being on your feet you could lay down and still use your computer.
Like this you avoided sitting completely, which is especially bad for you, and replaced it with three movements that are alternated so you can avoid other types of injury.
If you are in a rigid environment where you don't have a lot of freedom, you can at least minimise the damage you do to your back by changing the way you sit you can read more about that in this post...., and maybe take breaks more often and move around.
So like changing your diet from an unhealthy one to a healthy one is important to know what foods are bad for you and whit what to replace it. Obviously sitting is the equivalent of junk food, in the list below are some examples of healthy movements that you can use to replace sitting all day:
Standing
Squatting
Walking
Laying
Knelling
Lifting and manipulating objects with your hands
Bending from the hips
Remember to alternate this, even if they are healthy and won't deform your body, you still have to alternate them to avoid other injuries.