It is an offence to resist arrest.
Active resistance is required for a charge of resisting arrest to be laid.
Lying down and refusing to co-operate is not resisting arrest. Police may arrest you if they reasonably believe you have committed an offence, even if, in fact, you are completely innocent. If you resist arrest, you are committing an offence with which you may be charged, even if the police do not charge you with any other offence.