noun
knuckle-walking
Technical term used in primatology and zoology for locomotion on the dorsal surface of the middle phalanges, as seen in chimpanzees and gorillas.
チンパンジーは指背歩行で移動することが多い。
Chimpanzees often move by knuckle-walking.
Compound of 指 (finger), 背 (back), and 歩行 (walking), literally 'finger-back walking', describing the knuckle-walking gait.