The medium is the massage, and the massage is a T-Shirt. A T-Shirt with a railroad play mat and accompanying locomotive, baby! And baby daddies! Becky of bkykid must be the envy of all moms who fancy themselves clever craft masters but who were not clever or crafty enough to conceive this sweet, sleeved means of tricking kids into being their parents' servants. Hey, they're the reason your shoulders are knotted and your low back seized up in the first place, I don't see anything wrong with bamboozling them into helping rectify the discomfort.
Railroad play mat T-Shirts invite massages across a 12" x 15" printed design. Shirts come in standard--not fitted, metro-men--male sizes S through 2XL.
If I had a kid between the ages of 2 and...how old are kids when they stop playing with trains, like, 12?...yeah, so between 2 and 12, I would require him (I'm positive I'm genetically coded to produce only boys) to massage my back for 30 minutes every day before allowing him to watch cartoons or play video games or eat food.