Rush were riddled with physical issues over the course of their R40 tour, as the new documentary Time Stand Still makes clear. But don't expect the band to ever take the road without drummer Neil Peart or guitarist Alex Lifeson, who have dealt with (respectively) chronic tendinitis and arthritis.

"We always said that if the three of us aren't on board, we don't do a thing," frontman Geddy Lee says in Time Stand Still (via Rolling Stone). "So, one guy doesn't want to do that thing anymore that I love to do. That hurts. But there's nothing I can do about it and that's part of the agreement."

Time Stand Still chronicles a 35-date North American tour that marked Rush's 40th anniversary. Band members have said that it will be their last major jaunt. The documentary makes clear just why, as Peart ends up dealing with a debilitating foot problem in addition to his tendinitis.

The drummer, who said he wanted to be closer to home for his new daughter, admits to flying into a rage over the prospect of returning the stage in the first place. "I felt trapped," says Peart, who replaced John Rutsey in 1974. "I was stomping around and cursing. But by the next day it was like, 'It is what it is. Deal with it!'"

A fan of traveling from show to show on his motorcycle, Peart ended up developing a fungus after riding through torrential storms with wet boots. That then developed into eczema psoriasis and a series of bacterial infections. Suddenly, walking – much less playing drums for hours on end – became unbearable. But Peart soldiered on, even it meant playing on "two raw stumps," as he described them. "He's such a stoic guy," Lifeson says. "I can't believe he played through that."

When the tour drew to a close on Aug. 1, 2015, at the L.A. Forum, an emotional Peart could be found – in a very rare moment – at the front of the stage, joining Lee and Lifeson in a final bow. "I've never crossed what I call the back-line meridian," Peart says. "I stay behind my drums and cymbals for 40 years and never go out front, never. It's not my territory. Eventually, I talked myself into it. ... It was totally the right thing to do."

Time Stand Still will be presented in a one-night-only Fathom Events screening nationwide on Thursday.