If you use a MacBook Air without a laptop stand, you will probably have chronic neck, back and wrist injury in a few years. This is very serious.
Here’s the problem. See that neck position? It’s always pointed 45deg down. That’s not your neck’s natural position. So what happens is your nerves get compressed in your neck and shoulder. Also the nerves that lead up to your wrist and hand. That (and more) gives you the tingle feeling of RSI/CT.
Most cases of persisting RSI have their basis in the nerves that run from the neck, down through the shoulders, and into the wrists and hands.
It’s easily fixable though but you need to be consistent about it.
The top of your screen should be at eye level. Thus, you should get a stand that raises your laptop. This is the one I use http://www.therooststand.com/
An external mouse and keyboard are also important. I have a Logitech MX Performance mouse and an Apple Wireless Keyboard.
Your arms and hands should be flat on the table and not angled up or down ward. Your elbow should be close to a 90 degree angle, although your arm and hands can extend more into the table.
If you don’t, you get chronic issues. I have them. Although they go away when I’m in an ergonomic position.
I think @Casey_Rosengren from Hacker Paradise has chronic issues too because he didn’t pay attention early on to work ergonomically. Most nomads get it because they’re stubborn. Don’t be! It’s your health.