YOU SAID:

He thrusts his fists against the posts.

INTO JAPANESE

彼はポストに拳を突きつけます。

BACK INTO ENGLISH

He sticks his fist at the post.

INTO JAPANESE

彼は拳を握りしめます。

BACK INTO ENGLISH

He clenches his fist.

INTO JAPANESE

彼は拳を握り締めます。

BACK INTO ENGLISH

He clenches his fist.