Objective To identify potentially-misleading terms and concepts in concussion biomechanics.

Design Literature review.

Setting N/A.

Participants N/A.

Intervention N/A.

Outcome measures Media articles and scientific literature describing potentially-misleading terms and concepts in concussion biomechanics.

Main results Potentially-misleading terms and concepts in concussion biomechanics were identified in media articles, clinical textbooks and some scientific articles. One such misconception is that during a concussion the brain ‘sloshes’ and slams into the skull. The brain, which has very high water content, is nearly incompressible and is tethered to an almost rigid cranial cavity. Therefore, the brain resists separation from the skull during radial impacts; however, there is little resistance to shear during oblique impacts, which results in brain tissue deformations. Another potentially-misleading concept is that the mass of headgear increases the angular acceleration of the head during an impact. Such a concept is incorrect as the mass of the headgear increases the moment of inertia of the head and, therefore, decreases the tendency of the head to rotate. Lastly, the term ‘sub-concussion’ originally referred to animal model head impacts not resulting in loss-of-consciousness. However, ‘sub-concussion’ is currently used to refer to any head impact not resulting in concussion, e.g. head accelerations experienced by a soccer player when heading a ball. A biomechanical threshold for concussion has yet to be identified; therefore, careful use of the term ‘sub-concussion’ is suggested.

Conclusions Potentially- misleading terms and concepts in concussion biomechanics have the potential to misinform and confound attempts to further the understanding of concussion.

Competing interests None.