Changes in coordination could mean many things from nerve and muscular strength issues, to more serious underlying conditions such as MS and such. However, you do sound like you've been in some traumatic crashes so maybe you've got some serious muscles imbalance and trigger point issues. I'd explore all avenues to figure out what's going on. The quick check is the trigger point stuff. A physio or massage therapist well versed in it will be able to tell relatively quickly if that is the issue. If that doesn't pan out (is that just a North American term? Meaning the gold is not in the pan), then investigations into other neurological issues that can cause loss of coordination would be a good idea.