It happened on the B3081 near Verwood - he had to be cut free by firefighters.
Police Expecting Repeat Of Riots
Police expect a repeat of last summer's riots and are concerned about how budget cuts will affect their ability to deal with the unrest, according to a study into the disorder.
The majority of officers caught up in August's unrest believe similar rioting is likely, with many citing worsening social and economic conditions as the potential cause, the survey found.
They also fear their forces do not have the resources to cope with unrest on a similar scale.
A total of 130 officers from eight forces were interviewed as part of The Reading the Riots research conducted by the London School of Economics and The Guardian. Most gave anonymous accounts of the riots which spread across London, Birmingham, Liverpool, Manchester and Salford last summer.
Nearly all those interviewed described the unrest as the greatest physical and psychological challenge of their careers and officers of all ranks said they were astonished no colleagues were killed.
One superintendent from Greater Manchester Police said he expected more disorder within the year.
When asked if rioting will happen again, he said:
''I think if you have bad economic times, hot weather, some sort of an event that sets it off...my answer is: yes, it could.
''Because I don't think anything has changed between now and last August, and the only thing that's different is people have thought: riots are fun.''
Police generally rejected criticism of the tactics deployed during the trouble, but admitted they were stretched to the limit by the scale and speed of rioting and left totally overwhelmed in places.
Senior Metropolitan Police officers also accepted they struggled to deploy enough staff to contain the violence during the four days of disorder in the capital.
The study reveals the Met failed to activate a national alarm system to call for more resources until the third day of riots, and once officers from other forces did arrive they were hampered by poor communication with central command.
Forces across England also failed to fully act on intelligence gleaned from social media networks, which were used by rioters to outmanoeuvre police, the interviews revealed.
Officers from West Midlands, Merseyside, Greater Manchester, Cambridgeshire, Thames Valley, Hampshire, Surrey and the Metropolitan Police, were interview as part of the second phase of The Reading the Riots study.
Victims, so-called vigilantes and lawyers who dealt with the aftermath in the courts were also quizzed.
The first tranche of research, published in December, was based on confidential interviews with 270 rioters.
The latest data comes as the police service stares in the face of widespread budget cuts.
Paul McKeever, chairman of the Police Federation, said police would struggle to cope with further disorder if the proposed austerity measures went ahead and urged the government to take ''urgent stock'' of the results of the study.
''This comprehensive analysis demonstrates what we have been telling the Government for two years now; that a 20% budget cut to policing will have a negative impact on public safety and that police numbers really do matter.
''Officers interviewed rightly identify and voice concern that, should the same circumstances occur again, the police service would struggle to cope and contain the situation with the loss of police officers numbers we are experiencing as a direct result of the cuts - over 5,000 last year alone.''
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