Originally Posted by
unterhausen
Back soreness usually signals core strength issues. A lot of people have weak lower backs, I don't think youth is a guarantee that isn't the case. Cycling uses the lower back.
Those bikes were really long IIRC. Shorter stem might be a better fix than raising the handlebars.
Thanks for the quick response, I'll look into it, now that I think of it, not sure how bent his elbows are. So yes, if his arms have no bend then We'll def need a shorter stem.