I had this mornings first OMG flight from AVV to SYD on JQ. Caveat - this is not a JQ rant, and please don't turn it into one! A couple of minutes after top of decent (my timing may be wrong as I was dozing) the little A320 suddenly got thrown around like a rag doll in a storm. The turbulence was "jolty" and had the AC violently side to side with a reasonable drop thrown in. I have experienced wake turbulence before - this increased the heart rate a few beats, but quickly settled down as we were back in clear air again in a few short seconds - although I must admit it did seem longer! From a basically silent flight, there was suddenly a lot of nervous laughter and the lady in the window in my row was sobbing away - I think she had taken a decent whack on the head. The seatbelt sign came off and the flight attendants in front went through the cabin looking for injured PAX - quickly and with purpose in mind. Coming in to land, we had to pass through a lot of cloud - I took special note of the terror on some PAX faces I could see, the looking around and the tenseness as the plane was slightly buffeted by cloud bumps. I really did feel sorry for the once a year flyers. On landing the Capitan was on the PA informing us the turbulence was caused by a SIA eek380 passing through our descent path with less than the required 8 miles (i'm sure this will be corrected by our learned members) - quite close in fact...hmmm. I'm thinking CASA straight away... Anyway, all the PAX alighted with no injuries needing hospital treatment, however, the only male FA on the flight got hurt - the Capitan addressed this as well commenting that medical treatment would be sought after everyone had alighted the AC. A couple of points: 1. Everyone in my immediate forward view had seat belts on - I was in row 8 2. A number of seats reclined by themselves - this must have frightened the **** out of the person in the seat 3. A couple of overhead bins opened 4. Idiot PAX on leaving the AC opening bins from the rows behind and stuff falling out - I actually caught a laptop that would have hit the floor 5. The JQ staff on that flight could NOT have been more professional about how they went about the cabin checks after the event 6. Wake turbulence sucks!