Chuck is far more capable now then he was then - but IMO most of the footage is less than impressive due to the ruleset rather than any lack of ability
I actually practice this every day I'm down the gym for giggles. I even do roundhouse kicks on the speedball (or at least try to). Don't ask me why. I do it just because I can.
I cant do the van damme 360 kick yet but I do practice other "fancy kicks" that id never use in competition just for fun .
The kick itself is easy, Ive been able to do it for years, its the flexibility that needs most training so that it's done exactly the same. Otherwise it just ends up being a jumping spinning crescent rather than the chopper kick. If you can do a full split, and jumping spinning crescent kicks, you should pick it up fairly quickly. I'm actually surprised Van Damme still nails this kick today. I find it harder and harder to do as I get older, though maybe its more because I'm not as flexible as I was when I was a kid.
He said it himself on his reality show that from the constant years of doing that kick he screwed up his hips. He does not do it as much as he used to. In fact the past 10 years of movies he did, he MAYBE did a 360 kick in one of them. I know in Expendables 2 he's gonna bust one out since I already saw the preview pic.
For me, one of the best things that developed with age was what I call a "cost-benefit analysis" mentality when it came to training. Sometimes it has to do with a technique and sometimes it has to do with conditioning. I'm age 61 and I don't have any real problems with my joints or back, though a bit of trouble now and again with my neck. My hands, wrists, feet and ankles are all in pretty good shape. BUT this didn't happen by luck. Instead I drew the line at material that risked more damage to me than in providing an asset to my training. This crap about doing hundreds of kicks each day, hundreds of breakfalls, and all the rest of that garbage may help the teacher fill a class, but it does little or nothing for the longevity of the students MA career. IMHO. Best Wishes, Bruce