Johnathan Thurston's shoulders are so damaged that he cannot lift one man, but he's been cleared to continue carrying his North Queensland side to the NRL premiership.

Thurston was found not guilty of a dangerous throw by the NRL Judiciary after medical evidence emerged that the champion halfback requires surgery on both shoulders at the end of the year due to torn tendons.

The verdict means Thurston escapes a one-game ban and is cleared to play Manly in Saturday's preliminary final at the Sydney Football Stadium.

But the emergence of the full details of Thurston's injuries is only going to intensify the pressure on the two-times Dally M player of the year.

Such is the extent of Thurston's injuries, dating back to early in the season, he has been having regular cortisone injections and his orthopaedic surgeon Dr John Maguire says he cannot physically lift a player weighing over 100kg.

Thurston was charged with a lifting tackle on 102kg Warriors forward Wairangi Koopu but after a hearing which lasted an hour, the judiciary panel of former players Scott Tronc, Darren Britt and Don McKinnon, took just 10 minutes to decide on their not guilty verdict.

Thurston emerged with a broad grin and was ecstatic to be free to play the Sea Eagles for a shot at a second grand final.

"I'm very relieved," said Thurston.

"It's a big weight off my shoulders."

The Cowboys have a horrendous record without their star player, winning just 27 per cent of their games.

Such is their dependence on the Test and Queensland halfback, he has carried his shoulder injuries for almost the entire season knowing he requires surgery on both once the Cowboys' year is over.

As the chief playmaker in a talented side, Thurston is often targeted in defence and he revealed to the judiciary what lengths he goes to just to ease the burden on his shoulders including switching sides of the field and adjusting his technique.

"I defend third man in on the left but I try to swap to the right," he told the panel.

"Forwards are always targeting me.

"I just try to get good contact and then roll with the player."

It is this contact that his defence counsel and Manly Leagues Club board member Geoff Bellew SC argued was a "copybook style" and the result of "perfect positioning".

NRL prosecutor James McLeod, in just his third judiciary hearing, tried to convince the panel that Thurston's left arm had lifted Koopu's leg and was a "contribution of substance" to the up-ending motion of the tackle.

"It was more than an accident," said McLeod.

"More than the forces of the tackle conspiring to come up with this result."

But the panel ultimately agreed with Bellew and the defence's evidence from both Dr Maguire and Associate Professor Warwick Spinks who specialises in human movement and exercise science.

"Bearing in mind Johnathan's shoulder injuries, the lifting of a player weighing over 100kg would have been beyond his physical capabilities, even allowing for the corticosteroid injections," wrote Maguire in his report.

"This loss of strength has been apparent throughout the majority of the season, since his shoulder injuries both occurred early in 2007."

Thurston joked afterwards he would now make another alteration to his technique when the big boppers come running full steam his way.

"I will just let them run past me."

Brought to you by AAP © 2024 AAP