This particular ailment first reared its ugly head at the back end of last summer and saw yours truly hobbling around like an old man for a month until my father diagnosed the problem for me. A course of pain killers and muscle relaxants soon saw me back to rights again.
But two weeks ago, I awoke to find that familiar old twinge had come back to plague me, this time in the left side instead of the right.
But surely this has no bearing whatsoever on the long-term Lexus GS300, you say - and that's where you'd be wrong.
For the back problem has highlighted a rather bizarre phenomenon. There are only two positions where I feel properly comfortable - either lying flat in bed or sitting in this car.
My office chair, sculpted by Swedish ergonomics experts, doesn't do the trick and neither does my favourite lounger in the snug at the local. So I'd like to say a big thank you to who ever is responsible for seat design at Lexus headquarters - I owe you a large saki if I ever meet you.
And talking of phenomena, I came across another the other day - the Lexus anorak. This particular character was lurking around the pumps at my local Sainsbury's the other week, filling up his battered old Vauxhall Nova. 'Ere, my other car's one o' them,' he hollered across to me. I smiled wanly and continued filling my vehicle. His tank being somewhat smaller than mine, he finished first and came over to my side, chuntering on about how he would choose this model if he won the lottery and how lucky I was to own one.
Not wishing to be rude (and not wishing to own up that it wasn't actually my car), I made polite conversation, hoping he might go away if I simply agreed with everything he said.
But alas, no. He ended up behind me in the queue to pay and it was a good five minutes before I managed to escape to the refined luxury of the GS300's interior for a bit of peace and quiet.
But as I drove away, I had to admit that Mr Lexus Anorak was indeed correct in his praise - for the price, this car is just about the ultimate machine to transport up to five people from A to B in perfect opulence.
And after 11 years of the marque being on sale in Britain, it looks as though the message is getting through. For whereas residual values of many luxury cars are struggling, those of the GS300 are doing very nicely.
A glance at the Fleet News running cost tables which appear every month show that this model is predicted to keep 41% of its original value after three years/60,000 miles — just one point under the Mercedes-Benz E320 Elegance automatic.
As part of our ongoing long-term Lexus road test schedule, the car has been returned to headquarters just before it was due for its 10,000-mile service, to be replaced by the GS430 with its blistering V8 powerplant. Deputy editor John Maslen will be reporting on the delights of this car next month.