At the risk of sounding serious and therefore boring, allow me.
Quite alot of players wear them these days perhaps not in SL but across the amateur game. You don't tend to think you need them until you catch a shoulder or knee on the bicep. A dead bicep feels like a dead leag but about twice as bad IMO, and can probably keep you out for a couple of weeks if you catch one badly enough. I'm guessing Sinny (and Sean Long) have caught one before, and decided that padding would be a good idea.
Quite alot of players wear them these days perhaps not in SL but across the amateur game. You don't tend to think you need them until you catch a shoulder or knee on the bicep. A dead bicep feels like a dead leag but about twice as bad IMO, and can probably keep you out for a couple of weeks if you catch one badly enough. I'm guessing Sinny (and Sean Long) have caught one before, and decided that padding would be a good idea.