A Wollongong police officer suffered a dislocated shoulder when he was assaulted while on the job, police will allege.
About 7.45pm Saturday, police stopped a vehicle at North Wollongong and spoke to a number of occupants.
When they tried to stop a woman attempting to leave the scene, police allege a man assaulted a Senior Constable, dislocating his left shoulder.
The 45-year-old man was arrested and charged.
He will appear at Wollongong Local Court at a future date.