You could try Planetx i bought a couple a few years ago, i think i paid about £12 each they are not top of the range with earphones or anything like that but they do do the job, known through experience, like many of us last year, i hit a rock on my heal edge, head was ok back was very much in pain, oh and i am an adult but i swear by wearing one, so don't just buy one for the kids buy for the whole family. Jamesg