A vulnerable woman will spend weeks in hospital after a bike rider mowed her down and kicked her in the back during a “disturbing” random attack in Melbourne’s outer-west. Melinda, 52, was walking on Unitt Street in Melton on Tuesday afternoon when a man on a bike approached her from behind and launched a “sickening” attack. The woman suffered a broken knee cap, black eyes and cuts. She also smashed her head on the concrete, causing a concussion. The woman has undergone knee surgery, but will need to spend at least six weeks in hospital to recover, followed by a “lengthy” rehabilitation process. Detective Acting Sergeant Jessica Kas said the attack was “completely unprovoked”.