title: Why do woodpeckers resist head impact injury: a biomechanical investigation.
abstract: Head injury is a leading cause of morbidity and death in both industrialized and developing countries. It is estimated that brain injuries account for 15% of the burden of fatalities and disabilities, and represent the leading cause of death in young adults. Brain injury may be caused by an impact or a sudden change in the linear and/or angular velocity of the head. However, the woodpecker does not experience any head injury at the high speed of 6-7 m/s with a deceleration of 1000 g when it drums a tree trunk. It is still not known how woodpeckers protect their brain from impact injury. In order to investigate this, two synchronous high-speed video systems were used to observe the pecking process, and the force sensor was used to measure the peck force. The mechanical properties and macro/micro morphological structure in woodpecker's head were investigated using a mechanical testing system and micro-CT scanning. Finite element (FE) models of the woodpecker's head were established to study the dynamic intracranial responses. The result showed that macro/micro morphology of cranial bone and beak can be recognized as a major contributor to non-impact-injuries. This biomechanical analysis makes it possible to visualize events during woodpecker pecking and may inspire new approaches to prevention and treatment of human head injury.
authors: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, People's Republic of China.
authors: Lizhen
authors: L
authors: Wang
authors: Jason Tak-Man
authors: JT
authors: Cheung
authors: Fang
authors: F
authors: Pu
authors: Deyu
authors: D
authors: Li
authors: Ming
authors: M
authors: Zhang
authors: Yubo
authors: Y
authors: Fan
mesh_terms: D000818:Animals; D001502:Beak / Q000502:physiology; D001696:Biomechanical Phenomena; D001717:Birds / Q000293:injuries / Q000502:physiology*; D001930:Brain Injuries / Q000517:prevention & control*; D006259:Craniocerebral Trauma / Q000517:prevention & control*; D020342:Finite Element Analysis; D012886:Skull / Q000502:physiology; D014057:Tomography, X-Ray Computed; D014741:Video Recording