Women really do waddle like penguins when they are pregnant, research shows.
After filming various stages of pregnancy scientists found a baby bump changed a woman's gait from as early as three months.
Even during this first trimester, they found pregnant women's centre of mass was further forward, they leaned backwards while standing and they bent their hips less while walking.
This combination made them lose balance more frequently. Such accidental falls cause up to a quarter of trauma injuries during pregnancy, and an expectant mother has the same risk of falling as a 70-year-old.
The biomechanical model of pregnant women was created, allowing them to see how they adjusted their movements when doing things such as changing direction or getting up from a chair.
Professor Koichi Shinkoda, of Hiroshima University, Japan, said: "Biomechanics studies like ours of how humans move are valuable for many things, like making our built environments safer or designing mobility skills."
The team brought eight women into the lab at three different times during their pregnancy, as well as seven non pregnant peers. They used infrared cameras to record their movements and special flooring also measured the force of their step.
Contributing scientist Yasuyo Sunaga said: "We want to find the ideal way for mothers to carry their baby, what exercises are most effective to return to non-pregnant fitness, and what physical postures are best for work in the home or office."
Their study was published in the journal Applied Ergonomics.