After spending three weeks under the care of doctors, Renner returned home and, despite fears that he would never walk again, he appears to be doing remarkably well — even hitting his first red carpet since the accident in April.
Taking to social media on Wednesday, the American star shared a selfie with tubes in his nose while he used a hyperbaric oxygen chamber.
Renner captioned the snap on Instagram Stories: ”Sending love from O2 chamber.”
He also uploaded a short video showing him working out his legs, which are “filled with titanium”.
“Knees/ankles recalibrating. Strengthening around the titanium to set up for later rounds in life,” he wrote across the clip.
He revealed earlier this month that he is currently using a hyperbaric oxygen chamber twice a day.
The chambers create an environment in which users can breathe 100 per cent oxygen, as opposed to the 21 per cent found in air.
This means the lungs absorb more oxygen and pass it into the bloodstream, speeding up the healing process.