A 76-year-old woman was mugged twice in two weeks by the same robber.
Lee Davenport, from Stockport, was jailed for seven years and two months on Monday at Manchester Crown Court, after he admitted carrying out both muggings.
Greater Manchester Police (GMP) said Davenport snatched the woman's bag as she walked home from the supermarket on 10 June in Stockport.
His second robbery 13 days later left her needing hospital treatment.
GMP said the second attack by Davenport, of Mount Pleasant, Hazel Grove, left the woman with a severe injury to her right shoulder and "has meant the woman can no longer live alone and care for herself".
In the first robbery, Davenport threatened the woman on Bramhall Moor Lane, Hazel Grove, with a knife and snatched her bag which contained a bank card and her shopping.
Police said £300 was stolen from the woman's bank account before she had a chance to cancel the card.
Davenport robbed the woman again on 23 June near the George and Dragon pub after she went to buy a loaf of bread.
She needed hospital treatment after he yanked the bag from her shoulder and made her fall.
Det Con Jonathan Greenslade said: "This was an abhorrent and shocking pair of incidents which has caused immense distress to an innocent elderly resident in our community.
"To be a victim once is bad enough, but to be a victim of robbery twice is terrifying and it is even worse that the second time the lady was badly injured."