The key image in Old Partner is that of farmer Choi Won-kyun, 79, slumped in his jerry-rigged cart, being pulled down the rural South Korean roads between his tumbledown home and rice paddy by his 40-year-old ox. It’s a Methuselan age for a work animal. The thing seems ready to collapse with every trudging step. Won-kyun makes the trip several times daily. Old Partner is, likewise, a repetitive, lumbering journey toward an inevitable destination. This isn’t an insult—the subject determines the style. Director Lee Chung-ryoul, who dedicates his documentary film to a passing generation of rural grandparents, devotes close-up attention to the wear and tear of a lifetime of labor on beast and man. We scrutinize the ox’s rheumy eyes, festering patches, jutting hips, and flanks scaled with mud (or worse). Won-kyun and his wife, Sam-soon, are near bent in half; because of a shriveled ankle, he works the fields on all fours. Compared to, say, Raymond Depardon’s rural ethnographies, Old Partner is crude in its soundtrack-manipulated narrative and sentimental outbursts, awkward in an otherwise hard film. But one does leave with a rarely vivid sense of the grind of time, in work and marriage. NICK PINKERTON