We have done some basic stretching for the lower body, but when we sit for too long - especially if it is while working on our computer, or scrolling on our phones, we have to be sure to stretch our neck as well.
Think about your posture when you are at the computer - your head is either down or forward, which brings those shoulders forward and often rounded. This is going tighten your pecs and upper cervical spine, while lengthening and weakening your scapular stabilizers.
Here is a stretch that is meant to open your chest and extend the spine. While sitting on your chair, get tall. Bring your hands behind your neck, and extend the neck. Then push those elbows as wide as is comfortable to really open the chest.
Take a couple of deep, long breaths and feel those ribs move and expand.
From here, come back to sitting tall, and either leave your hands where they are, or reach them overhead. Get your back at tall as possible, and lean to one side and then then other.
This will lengthen the spine, and be sure to count to at least 10 on each side.
Taking the small breaks while sitting to intentionally move your body will save you a great deal of pain in the future.
These are some basic stretches, and there are plenty more that we can add to your routine.