「肌肉發達」、「四肢發達，頭腦簡單」的英文：all brawn, no brains

be all brawn and no brain(s): 肌肉發達，頭腦簡單
brawn是「體力；發達的肌肉」，be all brawn and no brains指一個人雖擁有良好體能卻缺乏聰明才智，或是說一個人總是用蠻力，而不懂得動腦思考。
He may have been a good football player in high school, but he was all brawn and no brains, so he didn't get into any colleges. 他或許是個優秀的足球選手，但他四肢發達，頭腦簡單，所以沒能進任何一間大學。