Waaaay back in the day, when I was in cosmetology school, we learned how to do scalp massage. The idea is that massaging your scalp stimulates blood flow to the roots of your hair, which brings more nutrients to it. This helps it grow.
Also, if your scalp muscles are tight due to stress, or just due to not having been massaged, it restricts that blood flow. So massage not only has immediate blood flow benefits, it will help increase blood flow to the scalp at all times.
So I decided to make a video showing exactly how scalp massage should be done.
By the way, there’s also lots more information on minimizing hair loss and stimulating regrowth on the gastric bypass hair loss page.