schouders eronder zetten

Etymology
lit. 'to put [one's] shoulders under it', referring to the physical action of lifting heavy objects on one's shoulders.

Verb

 * 1)  To work hard and make a strong effort; to put in the work.

Usage notes

 * Often, but not necessarily, preceded by the definite article.
 * Sometimes encountered with elision of the verb as an interjection of encouragement, e.g.: kom op iedereen, schouders eronder!