YOU SAID:

Except, your arms and legs are strapped down so that you can't move.

INTO JAPANESE

ただし、腕と足は縛られているので動けません。

BACK INTO ENGLISH

However, his arms and legs are tied so he cannot move.

INTO JAPANESE

しかし、腕と足を縛られているので動くことができません。

BACK INTO ENGLISH

However, he cannot move because his arms and legs are tied.

INTO JAPANESE

しかし、腕と足を縛られているため動くことができません。

BACK INTO ENGLISH

However, he is unable to move because his arms and legs are tied.

INTO JAPANESE

しかし、腕と足を縛られているため動くことができません。

BACK INTO ENGLISH

However, he is unable to move because his arms and legs are tied.