It certainly isn't a sport for the middle-aged. I get if you're a 40 something who like riding around on a longboard, but most have no business shredding the gnar. Bit of a PL:
I'm in my mid-30s, last year fell on my elbow when my board flung from under me when doing a kick-flip. Had to get an xray because I seriously thought I fractured something.
I used to fall from a lot higher, doing riskier stunts and tricks in my teens and early 20s, and walk it off (I fell grinding a rail down a set of stairs and busted my front teeth and tried it again). Now, something as simple as not sticking a kick flip on flat ground cost me a $200 ER bill.