Although the catapult phase of pilot ejections has been well characterized in terms of human response to compressive forces, the effect of the forces on the human body during the ensuing ejection phases (including windblast and parachute opening shock) has not been thoroughly investigated. Both windblast and parachute opening shock have been shown to induce dynamic tensile forces in the human cervical spine. However, the human tolerance to such loading is not well known. Therefore, the main objective of this research project was to measure human tensile neck failure mechanics to provide data for computational modeling, anthropometric test device development, and improved tensile injury criteria. Twelve human cadaver specimens, including four females and eight males with a mean age of 50.1±9years, were subjected to dynamic tensile loading through the musculoskeletal neck until failure occurred. Failure load, failure strain, and tensile stiffness were measured and correlated with injury type and location. The mean failure load for the 12 specimens was 3100±645N, mean failure strain was 16.7±5.4%, and mean tensile stiffness was 172±54.5N/mm. The majority of injuries (8) occurred in the upper cervical spine (Oc-C3), and none took place in the midcervical region (C3–C5). The results of this study assist in filling the existing void in dynamic tensile injury data and will aid in developing improved neck injury prevention strategies.

1.
Specker
,
L. J.
, and
Plaga
,
J. A.
, 1996, “
The K-36D Ejection Seat Foreign Comparative Testing (FCT) Program
,” Armstrong Lab Wright-Patterson AFB, Report No. AL/CF-TR-1996–0099.
2.
Bandstra
,
R. A.
, and
Carbone
,
L. S.
, 2001, “
Unusual Basal Skull Fracture in a Vehicle Equipped With an Air Bag
,”
Am. J. Forensic Med. Pathol.
,
22
(
3
), pp.
253
255
. 0195-7910
3.
Maxeiner
,
H.
, and
Hahn
,
M.
, 1997, “
Airbag-Induced Lethal Cervical Trauma
,”
J. Trauma: Inj., Infect., Crit. Care
1079-6061,
42
(
6
), pp.
1148
1151
.
4.
Perez
,
J.
, and
Palmatier
,
T.
, 1996, “
Air Bag-Related Fatality in a Short, Forward-Positioned Driver
,”
Ann. Emerg. Med.
,
28
(
6
), pp.
722
724
. 0196-0644
5.
Carroll
,
E. A.
,
Gordon
,
B.
,
Sweeney
,
C. A.
,
Joy
,
S.
, and
Connolly
,
P. J.
, 2001, “
Traumatic Atlantoaxial Distraction Injury: A Case Report
,”
Spine
,
26
(
4
), pp.
454
457
. 0362-2436
6.
Sances
,
A.
, Jr.
,
Myklebust
,
J. B.
,
Maiman
,
D. J.
,
Larson
,
S. J.
,
Cusick
,
J. F.
, and
Jodat
,
R. W.
, 1984, “
The Biomechanics of Spinal Injuries
,”
Crit. Rev. Biomed. Eng.
,
11
(
1
), pp.
1
76
. 0278-940X
7.
Mertz
,
H. J.
, and
Patrick
,
L. M.
, 1971, “
Strength and Response of the Human Neck
,”
Proceedings of the 15th Stapp Car Crash Conference
, Coronado, CA, pp.
207
255
.
8.
Van Ee
,
C. A.
,
Nightingale
,
R. W.
,
Camacho
,
D. L. A.
,
Chancey
,
V. C.
,
Knaub
,
K. E.
,
Sun
,
E. A.
, and
Myers
,
B. S.
, 2000, “
Tensile Properties of the Human Muscular and Ligamentous Cervical Spine
,”
44th Stapp Car Crash Conference
, pp.
85
102
.
9.
Yoganandan
,
N.
,
Pintar
,
F. A.
,
Maiman
,
D. J.
,
Cusick
,
J. F.
,
Sances
,
A.
, Jr.
, and
Walsh
,
P. R.
, 1996, “
Human Head-Neck Biomechanics Under Axial Tension
,”
Med. Eng. Phys.
,
18
(
4
), pp.
289
294
. 1350-4533
10.
Butler
,
J.
,
Pintar
,
F.
,
Yoganandan
,
N.
,
Myklebust
,
J.
,
Reinartz
,
J.
, and
Sances
,
A. J.
, 1988, “
Static and Dynamic Comparison of Human Cervical Spinal Ligaments
,”
IEEE Engineering in Medicine and Biology Society Tenth Annual International Conference
, pp.
679
680
.
11.
Panjabi
,
M. M.
,
Crisco
,
J. J.
, III
,
Lydon
,
C.
, and
Dvorak
,
J.
, 1998, “
The Mechanical Properties of Human Alar and Transverse Ligaments at Slow and Fast Extension Rates
,”
Clin. Biomech. (Bristol, Avon)
,
13
(
2
), pp.
112
120
. 0268-0033
12.
Schlick
,
M.
, 2002, personal communication.
13.
Maynard
,
S. T.
, and
Swanson
,
D. E.
, 1987, “
The CREST Windblast Protection System Design
,”
SAFE J.
17
(
4
), pp.
22
26
. 0191-6319
14.
Carter
,
L. A.
,
Pellettiere
,
J. A.
,
Perry
,
C. E.
, and
Wilson
,
D.
, 2000, “
Tensile Neck Injury Criterion Development
,”
SAFE Association 38th Annual Symposium
, Oct. 9–11,
Survival and Flight Equipment Association (SAFE)
,
Reno, NV
, pp.
43
49
.
15.
Weiss
,
M. S. L.
, and
Leonard
,
S.
, 1986, “
Guidelines for Safe Human Experimental Exposure to Impact Acceleration
,” Naval Biodynamics Laboratory, Report No. NBDL-86R006.
16.
Eppinger
,
R.
,
Sun
,
E.
,
Kuppa
,
S.
, and
Saul
,
R.
, 2000, “
Supplement: Development of Improved Injury Criteria for the Assessment of Advanced Automotive Restraint Systems - II
,” No. 208 Final Rule Docket: NHTSA-00-7013, National Highway Traffic Safety Administration, Washington, DC.
17.
Donelson
,
S. M. G.
, and
Claire
,
C.
, 1996, “
1995 Matched Anthropometric Database of U.S. Marine Corps Personnel: Summary Statistics
,” Geo-Centers Inc., Paper No. DAAK60-90-D-0002.
18.
Nightingale
,
R. W.
,
Winkelstein
,
B. A.
,
Knaub
,
K. E.
,
Richardson
,
W. J.
,
Luck
,
J. F.
, and
Myers
,
B. S.
, 2002, “
Comparative Strengths and Structural Properties of the Upper and Lower Cervical Spine in Flexion and Extension
,”
J. Biomech.
0021-9290,
35
(
6
), pp.
725
732
.
19.
McElhaney
,
J. H.
,
Hopper
,
R. H.
, Jr.
,
Nightingale
,
R. W.
, and
Myers
,
B. S.
, 1995, “
Mechanisms of Basilar Skull Fracture
,”
J. Neurotrauma
,
12
(
4
), pp.
669
678
. 0897-7151
20.
1990, “
The Abbreviated Injury Scale
,” Association for the Advancement of Automotive Medicine, Association for the Advancement of Automotive Medicine, Des Plaines, IL.
21.
Chancey
,
V. C.
,
Nightingale
,
R. W.
,
Van Ee
,
C. A.
,
Knaub
,
K. E.
, and
Myers
,
B. S.
, 2003, “
Improved Estimation of Human Neck Tensile Tolerance: Reducing the Range of Reported Tolerance Using Anthropometrically Correct Muscles and Optimized Physiologic Initial Conditions
,”
Stapp Car Crash J.
,
47
, pp.
135
153
. 1532-8546
22.
Aune
,
A. K.
,
Nordsletten
,
L.
, and
Ekeland
,
A.
, 1994, “
Passive Muscle Tension Augments the Anterior Cruciate Ligament. An In Vivo Study in the Rat
,”
Acta Orthop. Scand.
,
65
(
5
), pp.
538
540
. 0001-6470
23.
Van Ee
,
C. A.
,
Chasse
,
A. L.
, and
Myers
,
B. S.
, 2000, “
Quantifying Skeletal Muscle Properties in Cadaveric Test Specimens: Effects of Mechanical Loading, Postmortem Time, and Freezer Storage
,”
ASME J. Biomech. Eng.
0148-0731,
122
(
1
), pp.
9
14
.
24.
Kobayashi
,
M.
,
Takemori
,
S.
, and
Yamaguchi
,
M.
, 2004, “
Differential Rigor Development in Red and White Muscle Revealed by Simultaneous Measurement of Tension and Stiffness
,”
Forensic Sci. Int.
,
140
(
1
), pp.
79
84
. 0379-0738
25.
Spitz
,
W. U.
, and
Fisher
,
R. S.
, 1993,
Spitz and Fisher's Medicolegal Investigation of Death: Guidelines for the Application of Pathology to Crime Investigation
,
Thomas
,
Springfield, IL.
26.
Borchers
,
R. E.
,
Gibson
,
L. J.
,
Burchardt
,
H.
, and
Hayes
,
W. C.
, 1995, “
Effects of Selected Thermal Variables on the Mechanical Properties of Trabecular Bone
,”
Biomaterials
0142-9612,
16
(
7
), pp.
545
551
.
27.
Matter
,
H. P.
,
Garrel
,
T. V.
,
Bilderbeek
,
U.
, and
Mittelmeier
,
W.
, 2001, “
Biomechanical Examinations of Cancellous Bone Concerning the Influence of Duration and Temperature of Cryopreservation
,”
J. Biomed. Mater. Res.
,
55
(
1
), pp.
40
44
. 0021-9304
28.
Woo
,
S. L.
,
Orlando
,
C. A.
,
Camp
,
J. F.
, and
Akeson
,
W. H.
, 1986, “
Effects of Postmortem Storage by Freezing on Ligament Tensile Behavior
,”
J. Biomech.
0021-9290,
19
(
5
), pp.
399
404
.
29.
Kiefer
,
G. N.
,
Sundby
,
K.
,
McAllister
,
D.
,
Shrive
,
N. G.
,
Frank
,
C. B.
,
Lam
,
T.
, and
Schachar
,
N. S.
, 1989, “
The Effect of Cryopreservation on the Biomechanical Behavior of Bovine Articular Cartilage
,”
J. Orthop. Res.
0736-0266,
7
(
4
), pp.
494
501
.
30.
Panjabi
,
M. M.
,
Krag
,
M.
,
Summers
,
D.
, and
Videman
,
T.
, 1985, “
Biomechanical Time-Tolerance of Fresh Cadaveric Human Spine Specimens
,”
J. Orthop. Res.
0736-0266,
3
(
3
), pp.
292
300
.
31.
Gottsauner-Wolf
,
F.
,
Grabowski
,
J. J.
,
Chao
,
E. Y.
, and
An
,
K. N.
, 1995, “
Effects of Freeze/Thaw Conditioning on The Tensile Properties and Failure Mode of Bone-Muscle-Bone Units: A Biomechanical and Histological Study in Dogs
,”
J. Orthop. Res.
0736-0266,
13
(
1
), pp.
90
95
.
32.
Leitschuh
,
P. H.
,
Doherty
,
T. J.
,
Taylor
,
D. C.
,
Brooks
,
D. E.
, and
Ryan
,
J. B.
, 1996, “
Effects of Postmortem Freezing on Tensile Failure Properties of Rabbit Extensor Digitorum Longus Muscle Tendon Complex
,”
J. Orthop. Res.
0736-0266,
14
(
5
), pp.
830
833
.
33.
Menz
,
L. J.
, 1971, “
Structural Changes and Impairment of Function Associated With Freezing and Thawing In Muscle, Nerve, and Leucocytes
,”
Cryobiology
,
8
(
1
), pp.
1
13
. 0011-2240
34.
Nuckley
,
D. J.
,
Hertsted
,
S. M.
,
Eck
,
M. P.
, and
Ching
,
R. P.
, 2005, “
Effect of Displacement Rate on the Tensile Mechanics of Pediatric Cervical Functional Spinal Units
,”
J. Biomech.
,
38
(
11
), pp.
2266
2275
. 0001-6470
You do not currently have access to this content.