I've injured the LCL's in both knees a combined 10 times in the last 20 years, though incredibly never in rubber guard - it always happens in bizzarre situations like when I spin to take the back or in the truck or shooting for a low single. It always happens with a really loud click like somebody flopping onto an old couch. Anyway, my recovery timeline is almost exactly the same every time:
- It pops, doesn't hurt immediately, just feels kind of fuzzy.
- The next morning, I can't bend the leg and can't put weight on it without severe pain.
- 2 days out I can walk and slightly bend it
- 4 days out and I'm back to cycling and yoga
- 1 week out, I'm doing moderate-weight (~225 for me) squats and light rolling
- 2 weeks out, I'm doing everything 100% but not doing any risky moves with it
- a month out, I'm doing everything 100%
- 6 months out, I can no longer tell it's hurt
So basically, it doesn't stop me from training for very long; around 4 or 5 days. However, it still hurts and aches for about 6 months. In my experience, you don't want to just rest with it straight for more than the first day or two; after that, start moving on it.