Are there many working actors right now who are better than Joaquin Phoenix? Once best known as the younger brother of the late River Phoenix, the three-time Oscar nominee has spent the better part of the past two decades metamorphosing into one indelible character after another. But it’s not just his physical transformations that set him apart. It’s the dramatic range and mental states of the personas he inhabits.

In Lynne Ramsay’s April release You Were Never Really Here, Phoenix took on a frightening new shape, filling out his frame with knotty muscle, a drinker’s belly and a bushy graying beard as an Iraq war veteran, while granting us a glimpse inside the mind of a broken man with little to live for.

Phoenix now turns in another masterful performance in Don’t Worry, He Won’t Get Far on Foot, director Gus Van Sant’s slightly sentimental biopic based on the life of late cartoonist John Callahan, who survived a 1972 car crash that left most of his body paralyzed at age 21. Literally broken, Phoenix’s crimson-haired Callahan is confined to a wheelchair for much of the film, forcing the actor to rely almost exclusively on the use of his head, but for the limited mobility of his arms. Barely able to clutch the pen he uses to create Callahan’s single-panel comics, Phoenix’s hands become the blunt instruments that Callahan gradually learns to use again as he draws the uniquely simple yet rough figures that featured prominently in his politically incorrect strips. The boundary-pushing subjects of his cartoons sometimes led to boycotts and protests against Willamette Week, the Oregon newspaper that carried his aggressive and outrageous work from 1983 until his death in 2010. Instead of being a detriment, the physical restriction frees Phoenix to focus on the self-deprecating style that fuels Callahan’s humor, both in his comics and his path to recovery that serves as the spine of this sketch-like film.

The recovery that Van Sant focuses on, however, isn’t quite what you might expect. Rather than a treacly look at a young man coming to terms with a body that will never be the same, the filmmaker chooses to dramatize Callahan’s battle with the bottle as well as the relationships he develops in his struggle to overcome the alcoholism that began at age 12, “to hide the pain of abuse.” Entering into Alcoholics Anonymous, Callahan gains a support group of fellow addicts (a motley crew portrayed by Udo Kier, Beth Ditto, Mark Webber, Ronnie Adrian and Sonic Youth’s Kim Gordon) and a sponsor named Donnie, a well-heeled, homosexual hippie played by a bearded, long-locked Jonah Hill. Cast wildly against type, the usually comedic Oscar nominee rises to Phoenix’s level, embracing his character’s contradictions as Donnie refuses to offer pity over tough love.

Building off of a narrative device that he employed in his previous biopic, Milk, Van Sant cuts between a nonlinear series of speaking engagements in which Callahan tells the same stories about his life at different points in time—both in pre- and post-accident settings. The Oscar-nominated director of Good Will Hunting skirts the inherent conventionality of that flashback approach by also incorporating some of Callahan’s comics, expanding them into crudely animated interludes that retain their creator’s spirit.

And while some of the standard biopic tropes remain in place—including unresolved mommy issues and romance that develops between Callahan and Annu, one of his physical therapists (played by Phoenix’s current girlfriend, Rooney Mara)—Van Sant smartly opts to skip the artist’s later life by narrowing in on the program that brought Callahan back from the brink.

Van Sant zeroes in on step nine of Callahan’s recovery for the film’s emotional climax, a montage that features a tearful apology tour and the inevitable reunion with Dexter (Jack Black), the unharmed driver of the car that crashed into a pole at 90 mph, changing Callahan’s life forever. The catharsis between these former drinking buddies may remind you of the forgiving hugs between Matt Damon and the late, great Robin Williams in his Oscar-winning performance in Good Will Hunting, but luckily Phoenix and Black don’t overplay the moment.

In short, Don’t Worry, He Won’t Get Far on Foot, which is based on Callahan’s memoir of the same name, walks a fine line as it balances the acidic irreverence of the cartoonist’s humor with Van Sant’s sentimental streak. And while the end result might not appeal to all tastes, there’s no denying the rich performances that the director has drawn from everyone in his cast, but most notably from Phoenix, who’s helped Van Sant wheel past the cliches to deliver his most emotionally complex movie since Milk.

Don’t Worry, He Won’t Get Far on Foot ★★★ 1/2

Starring Joaquin Phoenix, Jonah Hill, Rooney Mara, Tony Greenhand, Beth Ditto, Mark Webber, Ronnie Adrian, Kim Gordon, Udo Kier, Carrie Brownstein, Ethan Tindukasiri, Sunny Suljic, Cree Kawa, Nolan Gross, Leo Phoenix, Rebecca Field, Olivia Hamilton, Heather Matarazzo and Jack Black. Written by Gus Van Sant, based on a book by John Callahan. Directed by Van Sant. At Boston Common, Coolidge Corner and Kendall Square.