Researchers at the University of Sheffield have successfully used computer simulated models and medical imaging to test the strength of young children's bones, producing results which could help car seat manufacturers design safer car seats for young children.

The study, the first on infant bone strength in relation to age/weight using models developed from modern medical images, is published in the Journal of Biomechanics and Modeling in Mechanobiology.

The research used CT scans — x-rays to take detailed pictures of the bones from different angles — and subsequent computer models to set up scenarios looking at how a different amount of force affects the bones, bending and twisting the bones to detect the breaking point.

These non-invasive techniques created 3D models of the femur (thigh bone) in the study of children's bones in the newborn to three-year-old age range.

This is the age range that has had the least research conducted previously but also the ages where children cannot talk or communicate effectively about how their injury occurred. There is also a period of rapid growth between these ages, and the researchers were able to determine how bones developed during this time and how bone strength changed.

Protection has improved significantly since the introduction of car seats but car accidents are still a leading cause of life-threatening injury in children. Computer-aided engineering is an essential part of vehicle development and safety assessments are increasingly relying on simulations. Therefore, it is vital that the correct simulations, using accurate models, are used to ensure optimum safety.

Current testing for car seats in simulated crash tests often uses scaled-down models of adults to simulate a child in a given situation. However, anatomically, a toddler has a very different bone structure to an adult — the bones are not fully formed and still growing.

Dr Amaka Offiah, Reader in Paediatric Musculoskeletal Imaging in the Department of Oncology and Metabolism at the University of Sheffield, and Honorary Consultant Paediatric Radiologist at Sheffield Children's Hospital said: "Bone fractures are common in childhood and have been estimated to account for 25% of all pediatric injuries. They can broadly be categorized as accidental or inflicted injuries.

"Currently, distinguishing between these can often be extremely difficult. Due to the difficulties in obtaining pediatric bone samples, there has been a lack of research to provide evidence-based information on bone strength in young children.

In addition to the child safety industry-based applications, the findings from our study can be used in future to aid clinical diagnosis. If we can provide a table which shows bone strength by age range for different bones in the body, we can then calculate the force required to break that particular bone.

Professor Damien Lacroix, Director of MultiSim, said: "The MultiSim project provided resources for this research, as the research team were able to use the same modeling techniques and software we created to look into musculoskeletal diseases and apply this to modeling for children's bones to test their strength.

"The potential applications of this research are far-reaching and demonstrate how computer simulations can potentially save time and provide a more reliable diagnosis for clinicians."