It happened on the B3081 near Verwood - he had to be cut free by firefighters.
Appeal Over One Stop Robbery
Detectives in Bournemouth are investigating a robbery at a store in the Boscombe area of the town - they've released a CCTV still.
It happened at approximately 4.45pm on Sunday 21st October at the One Stop Community Store on Seabourne Road.
A man entered the shop as a woman left the store. He then threatened a member of staff and requested money from the till.
No weapon was seen.
The cashier handed over money from the till and the offender ran out of the store across Cromwell Road along Seabourne Road in the direction of Southbourne.
Detective Constable Neil Third, of Poole and Bournemouth CID, said:
“Following enquiries I am able to release CCTV images.
“I am very keen to speak to the man pictured as he may have information which will assist in our investigation.
“If anyone recognises the man, I would ask them to contact me urgently.
“I am also appealing to the female customer who left the shop at the time to contact police as soon as possible.
“I would urge anyone who saw a man loitering outside the One Stop shop prior to this incident or anyone who saw a man run away from the location to call Dorset Police on 101.”
Nobody was injured.
Violent crime was up 37% in the last year. Police say it's mainly due to a change in how offences are recorded.
Anne-Marie Ellement took her own life after claiming she'd been raped by two colleagues.
48 Zany Zebras sculptures were sold off to raise money for Marwell Zoo.
Recently Played Tracks
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
What's happening on the roads where you are?
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart.
Get some great ideas on how to advertise your business on radio, online and on mobile.