When Michael Clarke earned the nickname Pup as a young cricketer with unbelievable talent, he realised there was something else that set him apart -- chronic pain.

"I was a 17-year-old kid and I think I dived for a ball and hurt my back -- had a flare up -- that's when I realised I had something more than just a stiff back," Clarke said.

Clarke said this pain stayed with him throughout his international cricketing career and is a new ambassador for not-for-profit organisation Pain Australia.

"I think I can probably count on one hand the amount of test matches I've played with no pain," he said in a video for the organisation.

"When it's at its worst, it feels like a knife is scraping down the side of my back.

"One of the hardest parts of my day is putting my shoes and socks on every morning.

"I'll have days where I have to ask my wife to put my socks on."

Clarke's not alone -- a survey of 1000 people with chronic pain found 68 percent were unable to perform daily tasks or participate in social activities because of loss of sleep due to pain, while 50 percent said their pain negatively impacted relationships and work.