A 51-year-old man was kicked in the body and stamped on the head while out jogging.
Police said the victim was approached by a man outside Ben's Barbers, in Plains Road, Woodthorpe, at around 7.30am on Wednesday, April 10.
A Nottinghamshire Police spokesman said: "The offender asked the man what he was doing before hitting him in the head, possibly with a weapon, causing him to fall to the floor.
"While he was on the floor the man was repeatedly kicked in the body and the attacker stamped on his head as he tried to get up.
"The victim was taken to the Queen's Medical Centre for treatment where he required stitches for head and arm injuries."
Police have appealed for witnesses to come forward.
Hazardous Area Response Team called to incident and road closed causing delays to buses
The offender has been described a white, aged about 30, around 5ft 10ins tall and of thin build.
He was wearing blue jeans and a parka-style jacket which had a fur hood, officers said.
PC Mark Szeremeta, of Nottinghamshire Police, said: "This was a totally unprovoked and vicious attack on the victim.
"There would have been a number of vehicles driving along Plains Road who may have witnessed this incident or may have recorded dashcam footage."
Anyone with any information which may help the police investigation is asked to call Nottinghamshire Police on 101, quoting incident 99 of April 12.
Alternatively, Crimestoppers anonymously on 0800 555 111.
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