Peak head acceleration can thus be more than 2. Some researchers found head acceleration as high as Reports in medical journals have stated that impacts at speeds even as low as five miles per hour can cause significant neck and cervical injury, including whiplash and herniated discs. These injuries can lead to chronic pain, numbness, weakness, or functional limitations lasting months or longer.
Medical experts have reported that around 10 percent of car occupants hit in rear-end collisions will develop whiplash, and as many as percent of those who suffer from cervical soft tissue injuries after car accidents fail to reach a full functional recovery.
Whiplash injuries may take months or years to heal on their own and, in some cases, require surgery. Studies have also been conducted on the effects of rear-end collisions on babies in rear-facing seats. Academic Editor: Jun Xu. Received 08 Dec Revised 11 Feb Accepted 13 Mar Published 04 Apr Abstract The objective of the present study is to investigate the influence of neck muscle activation on whiplash neck injury of the occupants of a passenger vehicle under different severities of frontal and rear-end impact collisions.
Methods and Materials An active human head-neck FE model was developed and the mechanical property of the neck muscle was described via a three-element Hill-type model with both passive and active properties. Collision FE Model 2. Figure 1. Figure 2. Schematics of the three-element Hill-type muscle model. Figure 3. The curves for setting the activation level and trigger time for the neck muscles. Figure 4. Figure 5. T1 acceleration in the anterior-posterior direction for a frontal impacts and b rear-end impacts.
Figure 6. Disruption of ligaments under different collision severities: a frontal impacts and b rear-end impacts. Rotations deg. Table 1. Peak head rotations and relative vertebral rotations for each collision severity flexion is positive rotation. Table 2. Figure 7.
The calculation parameters of neck injury criterion in frontal collisions. Figure 8. The calculation parameters of neck injury criterion in rear-end collisions. References H. Yao, M. Svensson, and H. Fice and D. Walton and J. Yu, R. Stokell, and J. McConnell, R. Howard, J. Poppel et al. Ono, K. Kaneoka, A. Wittek, and J. Shateri and D. Pramudita, S.
Kikuchi, I. Minato, and Y. Siegmund, B. Heinrichs, D. Chimich, and J. Luan, K. Yang, B. Deng, P. Begeman, S. Tashman, and A. The head angular acceleration refers to the speed of the rotation of the head around its axis see photos above , and the resultant linear head acceleration refers to the overall speed the head travels on a linear or horizontal plane. Reducing either or both of these factors would result in reducing the severity and duration of whiplash injuries.
The Institute found that more than 70 percent of all model passenger vehicles measured have poor head restraints. Fewer than three percent have head restraint designs with good geometry. Head restraints are neither high enough nor close enough to the back of the head to have the potential to protect many people in rear end collisions. Two factors determine the effectiveness of a head restraint. This distance should be small — the smaller the better.
The Add On Head Rest encourages the occupant to raise adjustable head restraints to the desired height and reduce the backset for maximum protection. In comparative tests, using human volunteers and multitudes of scientific equipment, a 73 percent decrease of head angular acceleration and a 38 percent reduction of the resultant linear head acceleration were documented when using the Add On Head Rest.
An accident reconstruction specialist, Rusty is a crash test volunteer and has performed more than crash tests. What I liked is that when I went back into the seat back, there was less of a neck rotation, head rotation backwards, significantly less.
Click here to see crash test photos and results. Call now and experience it yourself. The Add On Head Rest , for whiplash injury protection and relief from back pain and neck pain. Neck ligament injury was first detected at 5 g and at the C5-C6 spinal level. At higher impact accelerations, the injuries became more severe and spread throughout the neck. The researchers directly compared their findings with those obtained in their previous study of rear impact with head facing forward at the time of impact.
Rotated head posture at the time of rear impact caused significantly greater neck injury severity and more complex injuries, as compared to facing forward. They hypothesize that there are more severe and complex injuries for two reasons.
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