背せ伸のび

noun, noun or participle which takes 'suru', intransitive verb

standing on tiptoe and stretching; stretching oneself taller

Physical action of rising onto the balls of the feet and extending the body upward, often to reach something or appear taller.

• 棚たなの上うえの本ほんを取とろうと背せ伸のびした。

  I stood on tiptoe and stretched to reach the book on the top shelf.

• 写しゃ真しんを撮とるとき、みんな背せ伸のびして背せを高たかく見みせようとした。

  When taking the photo, everyone stretched up to look taller.

noun, noun or participle which takes 'suru', intransitive verb

overreaching oneself; trying beyond one's ability; pushing too hard

Metaphorical use: attempting something beyond one's current capacity, often with a nuance of straining or overextending.

• まだ初しょ心しん者しゃなのに上じょう級きゅう者しゃ向むけのコースに挑ちょう戦せんするのは背せ伸のびしすぎだ。

  You're still a beginner, so trying the advanced course is overreaching.

• 背せ伸のびせずに、自じ分ぶんのペースで勉べん強きょうするのが大たい切せつだ。

  It's important to study at your own pace without overstretching yourself.