I don't have formal training as a masseuse but I used to own a bunch of books on the topic of massage and had friends who were willing to let me practice on them. By the time I had kids, I was quite good at it. This was sometimes useful for helping my kids relax and feel better, but it also sometimes had much more impactful uses. The biggest impact it had was on helping one of my sons recover from a mild case of club foot. This just means his foot was bent inward slightly at birth. I took him to see a doctor about it when he was maybe two and the doctor said "Developmental. He will outgrow it." No, he did not outgrow it. When he was three or four, they finally put him in a cast to try to straighten the bones. Casting is something that can take months. If the clubbing is significant, they replace the cast with a new one every few weeks to gently press the bones into a straighter position. My son was only casted twice for a total of about a month and he got two casts...
Adventures in Parenting and Homeschooling My Twice Exceptional Kids