The incident is believed to have occurred in Carr View Avenue, Balby at around 4.30pm, when an unknown man is believed to have pushed her from behind.
The woman fell to the floor and the man is understood to have grabbed her bag and ran away towards Balby Road.
The woman suffered serious injuries that required hospital treatment.
Police have launched an investigation and are asking anyone who have seen the robbery or who has information that could assist the investigation to get in touch.
Please call police on 101, or email [email protected], quoting incident number 748 of 29 March 2016.
Alternatively you can call Crimestoppers anonymously on 0800 555111.