Women wounded more than men
Twice as many females than males were injured during and after the Canterbury earthquake, figures show.
A breakdown of injuries caused by the September 4, 2010 and February 22, 2011 quakes has also revealed the most common cause of injury across the disasters was falling or tripping.
Researching the Health Implications of Seismic Events (Rhise), group chairman Professor Mike Ardagh said more than 6600 people were injured in the February quake and 182 died in the initial 24 hours.
His research, published in The Lancet last year, proved more women than men - 69 per cent - were injured in the February 2011 quake despite the population being evenly spread.
"It is fascinating. We have a few hypotheses about why this is but have not proven anything yet," he said.
The most common injuries were lumbar, neck, shoulder and upper arm sprains, knee and lower leg bruises, rotator cuff, ankle and thoracic sprains, open leg wounds, shoulder or upper arm bruises and dental injuries.
Ardagh said the gender bias had whittled it down to three hypotheses:
The majority of the CBD population in Christchurch on February 22 was female.
Females behaved differently during and after the earthquakes and did "more injurious" things.
Fewer males made ACC claims than females.
"It could be claim-related behaviour, or it could be how people behave during earthquakes - that is a work in progress," Ardagh said.
The gender split across Christchurch was nearly even and ACC data showed that "under normal circumstances" more than 50 per cent of claimants were male, he said.
Professor David Johnston, of Massey University, has determined "mechanisms of injury" for nearly 9500 people injured in both quakes using Accident Compensation Corporation (ACC) data. His research has been submitted for publication in Natural Hazards.
ACC data shows 9427 people injured in the quakes, about 65 per cent - or 6099 ACC claimants - were women. It also shows that 1704 of those who fell from heights of up to 30 metres or tripped due to ground movements were women and 795 were men.
Women were also over-represented in nearly all other categories - "non-masonry projectile", "helping others", "tending to children", "tripping due to ground damage", "broken glass" and "animals injuring owners".
A total 407 women were injured tending to children, helping animals and helping others, compared to 194 men.
The mechanism that bucked the trend was "clean-up", which referred to tidying up damage to homes, workplaces and streets.
A total of 541 men were injured in that category across both events compared to 401 women.
Men were also over-represented in the category of injuries from falling bricks or stonework.