The woman, who suffered a minor injury to her hand in the attack in Clarendon Park, Leicester, has told police the bag contained irreplaceable photographs of her grandchildren.
The attacker targeted the woman in Montague Road. He pulled her bag from her arm and ran away toward nearby Seymour Road, where he joined a second man. The victim has told police the bag also contained cash, bank cards and her bus pass.
The attack happened at 4.15pm on Thursday, April 29. Police only released details yesterday.
The man who jumped on her back is white, aged about 18 to 20 years old, 5ft 2in and slim. He was wearing a grey hooded top.