Analysis of the anatomical structure of woodpecker head and neck

Abstract

<p indent="0mm">Woodpeckers are able to peck wood at great force and high speed without sustaining neck injury. Unlike woodpeckers, humans are prone to whiplash injury during vehicle collisions as a result of hypsokinesis and anteflexion of the head and neck. In this study, the anatomical structure of woodpecker head and neck was analyzed based on histological evaluation of anatomy and reverse modeling of vertebrae, and an atlas of the anatomy of the primary muscles of woodpecker head and neck was constructed. The anatomical structure of the head and neck soft tissue and morphology of the cervical vertebrae were compared among woodpeckers, humans, and hoopoes to assess the shock resistance of the woodpecker head and neck special structure. We found that the span of the woodpecker rectus capitis ventralis is smaller than that of the hoopoe, the woodpecker rectus capitis lateralis is a single muscle tissue and is not separated from the complexus, and the oblique muscles that connect the ventral process of the upper vertebrate and the lateral process of the lower vertebrate do not exist in woodpeckers. These differences result in woodpeckers having more restricted head and neck rotation compared with hoopoes. Thus, woodpeckers sacrifice some range of motion to ensure greater stability, thereby avoiding neck injury during pecking. In addition, the woodpecker splenius capitis, which connects the os supraoccipitale and the upper cervical vertebra, increases the stability of the cranial-cervical connection, and the absence of the cervical intervertebral disc leads to a reduced range of cervical rotation. These anatomical differences may explain why woodpeckers are less prone to neck injury than humans.