Principal Investigator: Voigt R. Hodgson, Ph.D.
Institution: Guardjian-Lissner Biomechanics Lab, Dept. of Neurosurgery, Wayne State University School of Medicine, Detroit, MI 48202
Manuscripts:
National Operating Committee on Standards for Athletic Equipment football certification program. Hodgson, Voigt R., Med. & Sci. in Sports 7(3):225-231, 1975.
Abstract: Wayne State University, Department of Neurosurgery was contracted in 1971 by NOCSAE to develop voluntary standards for football helmets. Preliminary tests of representative football helmets on cadavers and the Z-90 metal head form showed that a more realistic head model was necessary before it was possible to understand helmet performance. A synthetic model was developed which approached human cadaver performance and at the same time was more rugged and repeatable than a cadaver head. A test method was devised and a human tolerance limit of 1500 Severity Index based on resultant CG head accelerations was adopted as the performance standard. All new football helmets available for use in high school and college football have now been certified by the NOCSAE standard and the wearing of such helmets is mandatory for college players in 1978 and high schools in 1980. By means of design or material changes, certified helmets on the NOCSAE test are performing at a Severity Index level of 1/2 those posted by prestandard models, on the average. Experience with the equipment at a helmet reconditioning plant shows that 25% of precertified helmets being received are rejected and 84% of the remainder are testing on the front location (most critical) above a Severity Index of 1450, and should be replaced as soon as possible with certified helmets.
Head injury criteria and evaluation of protective head gear. Hodgson, Voigt R. ASME 31:121-135, 1976.
Abstract: A human-responding surrogate headform has been developed for the purpose of assessing the performance of protective headgear and reducing head injury in sports through improved helmet design. An outline of the basic requirements necessary to achieved such goals is given in this paper.
Spinal injury at the level of the third and fourth cervical vertebrae from football. Torg, J.S., Truex, Jr., R.C., Marshall, J., Hodgson, V.R., Quendenfield, T.C., Spealman, A.D. and Nichols, C.E. J. of Bone and Joint Surg., 59(8)1015-1019, 1977.
Mechanisms of cervical spine injury during impact to the protected head. Hodgson, Voigt R.* and Thomas, L. Murray*: (1980) Proc. of 24th Stapp Car Crash Conf., SAE, Troy, MI., pp.17-42, 1980.
Abstract: Static and impact loading of the heads of embalmed cadavers wearing protective helmets have been conducted for the purpose of understanding the mechanics of fracture-dislocation injury to the cervical spine. Some of the cadavers were cut down on one side of the neck for high-speed photographic observation of the spine during impact. Others were instrumented with strain gages to the bodies and near the facets to assist in correlating spine movements and load configuration with strain distribution. Results indicate that static loading can be a useful predictor of failure site under dynamic conditions. Those conditions which were found to be most influential on the injury site and level of strain were: 1) the extent to which the head was gripped by the impact surface to allow or restrict motion at the atlanto-occipital junction; 2) Impact location; and, 3) Impact force alignment with the spine. It was found that very little could be done with energy-absorbing material in the crown to reduce spine strain due to a crown impact. Also, the rear rim was not a “guillotine” threat to fracture dislocation from blows which cause hyperextension, and the higher cut rear rim recommended to reduce or eliminate this alleged hazard caused higher strain by virtue of allowing greater extension of the neck.
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