PubMed · 11360879
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Y M Wong. 2001. Accelerometer and mechanomyogram.. https://doi.org/10.1016/s0021-9290(00)00190-1
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The S-100B protein is a recognised indicator of traumatic brain damage, but the impact threshold at which S-100B is released into serum still remains unknown. The aim of the study was to investigate whether moderate shear forces are able to release S-100B into serum in people who did a bungee jump. Eleven healthy probands jumped from a height of 50 microm and were exposed to an acceleration of about 2.8 g. Blood samples were drawn before the jump, immediately after and 71 min (mean) after the jump. The initial serum values of S-100B of all probands were normal (mean 0.22 microg/l). Also the serum values directly after and 71-min (mean) after the jump showed no increase of S-100B (0.22 microg/l and 0.23 microg/l, mean). This finding indicates that a moderate acceleration and deceleration force to the brain does not activate the release of the protein S-100B into the serum.
The use of engineering principles in assessing head injury scenarios is of increasing significance in investigations into suspected child abuse. A fall scenario is often given as the history for a head injury to an infant. This paper addresses the basic engineering principles and factors to be considered when calculating the severity of a head impact after free-fall. The application of head injury models (HIMs) to ascertain the forces involved in childhood head injuries from impact is also discussed. Previous studies including Duhaime et al. [J. Neurosurg. 66 (1987) 409] and Nokes et al. [Forensic Sci. Int. 79 (1995) 85] have utilised HIMs for this purpose: this paper reviews those models most widely documented.The HIM currently considered the 'state-of-the-art' is the head injury criterion (HIC) and it is suggested that this model should be utilised for assessing head impact injury in child abuse cases where appropriate.
STUDY DESIGN: Human volunteers were subjected to a rear-end impact while sitting on a standard automobile seat, and sagittal plane kinematic responses were quantified. The effect of changing head restraint properties was determined by use of a repeated measures design. OBJECTIVE: To determine the forces acting, and relative motions resulting, on volunteers in a rear-end impact and the effect of head restraint properties. SUMMARY OF BACKGROUND DATA: In several recent studies of the kinematics of the cervical spine during rear-end impact, a forward thrust to the lower cervical spine was produced, and a transient S shape of the spine resulted while the head remained upright during the initial phase of the impact. This may result in nonphysiologic intervertebral motions and tissue strains. METHODS: Nineteen automobile seats were first tested, and a modified head restraint was designed. Each volunteer sitting on a standard vehicle seat was subjected to an impact pulse of 3g with a 4-kph speed change. Testing was performed first with the modified head restraint, then again after replacement by the head restraint that came with the seat. Kinematic responses were compared for both head restraints by use of a repeated measures analysis of variance. RESULTS: There was a measurable time difference between peak chest and peak head accelerations, which resulted in the chest being thrust forward by the seat back before the head was thrust forward by the head restraint. The modified head restraint significantly reduced the contact time difference and therefore decreased the relative chest-to-head forward motion. CONCLUSIONS: Volunteers seated on a standard automobile seat demonstrated differential sagittal plane motion between the chest and head. It is possible to significantly decrease the relative chest-to-head motion by altering the characteristics of the head restraint.