I remember my mother telling me stories about how foxes caught in traps would sometimes chew off their own legs to escape. I never thought I would hear anything similar involving a human being. That is, until I heard about Aron Ralston. The true account on which the magnificent “127 Days” is based is about nothing less than the ferocious indomitability of the human spirit. It is an ideal story for Danny Boyle because the director excels at putting characters in situations from which escape seems impossible. And then, seemingly at the last possible second, he injects hope — precious, unexpected, astonishing hope.

The story is so familiar it barely needs repeating. In 2003, the 27-year-old Ralston decided to hike Utah’s Canyonland National Park alone. He didn’t tell anyone where he was going. While squeezing through a narrow passageway, he slipped and fell, his arm trapped between the rock wall and a dislodged boulder. Five days later Ralston walked out of the canyon having severed his arm just above the elbow with a cheap utility tool.

Boyle (“Slumdog Millionaire,” “28 Days Later,” “Trainspotting”) is the most colorful, tactile, visceral director working today. His effervescent style here is put in service of character — an adrenaline junkie with an infectious love of life. When Ralston becomes trapped, the film and the countdown clock from which the title is derived truly begin.

From here on out, Ralston, as well as the actor who portrays him — James Franco, who will surely garner a Best Actor nod — is alone and nearly void of dialogue. Boyle’s task as captain of this ship is doubly difficult: He must eventually confront an uncomfortably graphic climax while also keeping us interested in watching just one actor on one claustrophobic stage. Boyle avoids the impending monotony by switching to interior mode, maintaining the film’s energy by living vicariously through Ralston’s imagination.

“127 Hours” doesn’t shy away from showing the inevitable deed. Indeed, the heroism is in the gore. The film is one of the great survival stories and easily one of the most inspirational, triumphal things you will ever see. You will walk out of the film elated. You may even find yourself wanting to pull on your hiking boots and hit a remote trail. Why? Because “127 Hours” is about ecstasy instead of agony, about triumph and not about defeat.

127 HOURS

Cast: James Franco, Kata Mara, Amber Tamblyn, Clémence Poésy, Treat Williams, Kate Burton

Director: Danny Boyle

Rated: R (for language and some disturbing violent content bloody images)

Running time: 1 hour, 35 minutes

Grade: A+

Photo by TMS