The hardened plastic cast keeps King's foot at 90 degrees to his leg, ensuring a constant stretch on his troubled achillies.
Speculation has grown in recent weeks that King may be forced to undergo surgery to correct the problem, effectively ending his season.
But club doctor Hugh Seward yesterday said the injury was showing signs of improvement since the ruckman a month ago began using the cast, otherwise known as a night splint.
``With the cast and a carefully controlled training regime, it is actually improving,'' Seward said.
``When you sleep your foot normally sags down but when you put this cast on it keeps the foot at 90 degrees to the leg. It maintains a degree of stretch on the achillies that stops it from stiffening up overnight.
The injury has plagued King since early in the season. He missed only one game, against Sydney in round eight, but has played on albeit under duress.
The dual club best and fairest winner has been on a modified training program since sustaining the injury and has been unable to take part in specialised ruck drills.
Amazingly, he is still second in the league for hit-outs behind West Coast's Michael Gardiner, however his mobility around the ground has clearly been affected.
He is averaging just 7.5 kicks per game compared with almost 11 last year and has run forward to goal only twice this year after kicking 14 last season.
Mark Thompson has had little option but to use King in the absence of a ready-made backup ruckman.
