The victim suffered a fractured pelvis as a result of the collision.
The incident happened in Church Lane, close to the junction with the church, at around 1.50 pm on Sunday (20th March).
The victim, in his 60s, was leaving a park in Charles Street, Coalville and was followed by four people riding motorcycles.
He got out of the car when something was thrown at his vehicle and it was at this point that one of the motorcycles collided with him causing him to fall to the ground. The group then left the area.
He suffered a fractured pelvis as a result of the collision.
Detective Constable Chrissie Hitchin, the investigating officer, said: “I’d like to speak to anyone who was in either Charles Street, Church Lane or travelling between the two locations on Sunday afternoon.
“Did you see a group on motorcycles? Did you see what happened? I am particularly keen to speak to anyone with a dashcam in their vehicle.
“Any footage or information you can provide could help my investigation.”
You can pass on information by visiting https://www.leics.police.uk/ro/report/ocr/af/how-to-report-a-crime/ and quoting reference 22*160786.