move your head
The German phrase 'Kopf bewegen' is a literal translation of 'move your head'. It is used in the same context as in English, for example, when giving instructions in sports or dance, or when describing a physical action. It is important to note that in German, the verb usually comes at the end of the sentence in subordinate clauses, unlike in English.
I have to move my head to ease the pain.
In this sentence, the speaker is stating a need to move their head in order to alleviate some pain that they are experiencing. The act of moving the head is expressed through the verb 'bewegen'.
He can move his head, but not the rest of his body.
This sentence introduces a contrast, stating that while the person can move his head, he is unable to move the rest of his body. The ability to move is indicated by the verb 'bewegen', used specifically in relation with the head (Kopf).
To fully read the sign, you have to move your head.
In this final example, the necessity to move one's head is being dictated by the need to fully comprehend the information presented on a certain sign. The sentence implies that without moving one's head (Kopf bewegen), one would miss out on some of the information.