After suffering from a severe RSI, involving wrist pain, numb fingers and months of physical therapy. This is what worked for me:
- If you are in pain, stop what you are doing. Be it working, stretching or exercising.
- Keep your wrists straight using a wrist brace, at day and night, until the pain goes away. There are soft braces specific for night use. One for day use that is not invasive is: https://www.amazon.com/BRACE-RCA-Treatment-Support-Regular/d...
- You can test your wrist posture by putting a pencil on your wrist. Your wrist should be straight. I emphasize this because it's one of the most contributing factors to RSI.
- Therapy alternatives include: physical therapy, medication, acupuncture. I did not try the acupuncture personally. Physical therapy was greatly useful, especially the stretches: https://www.youtube.com/watch?v=xAKOpnqvttI
- Use the right keyboard. A short keyboard helps your elbows, a mechanical keyboard helps your fingers. Ergonomic keyboards as well as vertical keyboards did not yield results for me. Even when used under the supervision of an ergonomist.
- Exercise does help. Muscles comes in pairs. Typing makes you contract your muscles more than you extend them, creating a muscle imbalance that contributes to carpal tunnel syndrome. These products help: https://www.amazon.com/PROCIRCLE-Finger-Stretcher-Resistance... , and when you need more: https://www.amazon.com/Strengtheners-rehabilitation-Equipmen...
Finally, see this as an investment. To be injured for life will put your career in jeopardy. Invest in your health.