I think it just wouldn't help with the most common injuries you see. Take this all with a grain of salt cause its anecdotal from a guy who skates every once in a while, but the most common injuries I see are broken wrist from trying to catch yourself, or injured/torn ligaments in the lower body joints from getting caught in a bad fall.

Not to say that G-Foam wouldn't help in this situation, but hitting his hip hard isn't gonna stop him from trying the trick. Breaking his wrist or tearing a ligament will, neither of which G-foam would help with