1. Keyboards & Mouse
Ideally you should use a separate keyboard and mouse while working for extensive period. The screen should be at arm's length while the keyboard needs to be pushed closer to the body which is not possible as you extend your hands while working on the laptop. This leads to slouching causing upper back pain.
2. Stable Base
Always have a stable base for your laptop where there is support for your arms, and not on your lap. Use tables with one end suspended so that it slides under your sofa bringing the table closer to your body instead of you leaning towards the screen.
Use laptop holders or tables in order to adopt good sitting posture with lower back support.
4. Take breaks!
Take regular breaks. If you’re moving, there’s a lot less stress on your muscles and joints.
5. Good Habits
Get into good habits before the aching starts. Back pains build up slowly and can cause severe damage.