Caring for your spine while using a laptop computer is complicated due to the nature of the laptop design. In normal seated conditions you would set up your ergonomics starting with your chair back rest position to make sure your shoulders are directly over your hips with support in your lower back. You then turn side on to your desk and make sure your elbow can gently rest on the side of the desk by changing the seat height. Then you would make sure that your knees are level with your hips by raising the feet. Then you would use a laptop raiser to bring the height of the top of the screen up closer to the height of your eyes, and then plug in a secondary keyboard and mouse. Please have a look at the diagram below for further reference.
It is then important to remember to regularly take breaks to stretch the back and the neck and reduce eye strain.