The prophet was directed to let the people see him sighing and prostrate, as a sign of the sorrow and weakness about to come upon the people.
The breaking of thy loins - The prostration of strength; the loins being the seat of strength.
Related Commentaries of Ezekiel 21:6
Ezekiel 21:6
6 Sigh therefore, thou son of man, with the breaking of thy loins; and with bitterness sigh before their eyes.