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Simulated Automotive Side Impact on the Isolated Human Pelvis: Phase I: Development of a Containment Device Phase II: Analysis of Pubic Symphysis Motion and Overall Pelvic Compression
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Abstract
PHASE I - A containment fixture was designed and manufactured to stabilize and preload isolated human pelves within a DYNATUP™ Drop Tower during simulated automotive side impact. The fixture was utilized during thirteen parametric tests aimed at determining boundary conditions which simulate inertial properties of whole cadavers during impacts of the isolated human pelvis. The resulting pelvic injuries (i.e., fractures) ranged from no fracture to complex acetabular fracture. These injuries were sustained with drop masses of 14.2-25.2 kg and impact velocities of 4.1-6.4 m/s. Peak force, measured during impact, ranged from 2.0-8.2 kN.
PHASE II - Phrase II studies used nine additional human pelves to explored pelvis stiffness and pubis symphysis mobility under lateral impact to the greater trochanter. The containment device designed and tested in Phase I was utilized to stabilize and compressively preload the specimens during impact. Preload was appropriately determined from the mass of each cadaver at death. Boundary conditions simulating the inertial properties of a pelvis with associated body mass were developed (i.e., during Phase I) and modified slightly for these impacts. Each specimen was constrained at the lower lumbar spine and ischial tuberosities with 40 grit sand paper while the contralateral iliac wing was supported by an adjustable metal shelf covered with 3 mm of flexible rubber gasket material. The right femur was held prior to impact (with break away restraints) in 90° of flexion and neutral internal/external rotation and abduction/adduction. The average impact velocity was 4.52 ± 0.06 m/s with an impact mass of 25.2 kg. The mean peak force was 5.03 ± 1.92 kN with an average time to peak force of 0.59 ± 0.20 ms. The resulting pelvic injuries (i.e., fractures) ranged from no fracture to nondisplaced acetabular fracture. The global motion of each specimen was captured with two KODAK EKTAPRO digital imagers calibrated to measure displacement of the pubic symphysis in the AP plane and lateral compression of the pelvis and pubic symphysis in the frontal plane. Motion analysis was completed with a KODAK EKTAPRO Hi-Spec Motion Analyzer. The average lateral displacement (i.e., in the direction of the impact) of the pubic symphysis during impact was 31.1 ± 8.1 mm. The average AP displacement was 0.6 ± 6.8 mm anterior to the position prior to impact. The average final position of the pubic symphysis was 19.7 ± 9.4 mm lateral and 1.9 ± 5.7 mm anterior to the original position. The average lateral compression across the pubic symphysis joint was 1.3 ± 0.04 mm; however, this measurement was at the resolution of the video equipment and was not believed to be accurate. It does indicate that the pubic symphysis exhibits a stiff response during simulated automotive side impact at 4.5 m/s. The average pelvic compression during impact as measured between the anterior inferior iliac spines was 11.2 ± 6.1 mm (5.87 ± 3.03 % pelvic compression). A detailed understanding of overall pelvic stiffness and symphyseal mobility could provide useful insights to enhance automotive safety in side impact collisions and improve anthropomorphic test dummy design.
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Citation
Molz, F., George, P., Go, L., Bidez, M. et al., "Simulated Automotive Side Impact on the Isolated Human Pelvis: Phase I: Development of a Containment Device Phase II: Analysis of Pubic Symphysis Motion and Overall Pelvic Compression," SAE Technical Paper 973321, 1997, https://doi.org/10.4271/973321.Also In
References
- Lewis, P.R. Molz, F.J. Schmidtke S.S. Bidez, M.W. A NASS-based investigation of pelvic injury within the motor vehicle crash environment Society of Automotive Engineers SAE # 962419 1996
- Grattan, E Hobbs, J.A. Injuries to the hip joint in car occupants British Medical Journal 1 71 73 1969
- Moffatt, C.A. Mitter, E.L. Pelvic fracture crash vehicle indicators Accident Analysis & Prevention 22 6 561 569 1990
- Pattimore, D. Ward, E. Thomas, P. Bradford, M. The nature and cause of lower limb injuries in car crashes Society of Automotive Engineers SAE # 912901 1991
- McDonald, S.T. Memnga, S.E. Vehicle impact location and its relationship to occupant injuries Society of Automotive Engineers SAE # 860200 1986
- Mackay, G.M. Hill, J.H. Parkin, S. Restrained occupants on the non-struck side in lateral collisions Accident Analysis & Prevention 25 2 147 152 1993
- Rouhana, S.W. Foster, M.E. Lateral impact: An analysis of the statistics in the NCSS Society of Automotive Engineers SAE #851227 1985
- Huelke, D.F. Anatomy of the lower extremity - An overview Society of Automotive Engineers SAE # 861921 1986
- Lau et al. A comparison of frontal and side impact: Crash dynamics, countermeasures and subsystem tests Society of Automotive Engineers SAE # 912896 1991
- Melvin, J.W. O'Day, J. Campbell, K.L. Robbins, D.H. Huelke, D.F. Side impacts: A comparison of laboratory experiments and NCSS crashes Society of Automotive Engineers SAE # 800176 1980
- Trella et al. Side impact crashworthiness design evaluation of padding characteristics through mathematical simulations Society of Automotive Engineers SAE # 912900 1991
- Bidez, M.W. Scales, V.L. Alonso, J.E. A preliminary report of intra-articular fractures of the acetabulum Proceedings of the 1st CDC Injury Prevention through Biomechanics Symposium 1991
- Busholz, R.W. Injuries of the pelvis and hip Emergency Medicine Clinics of North America 2 2 331 346 1984
- Eichenholtz, S.N. Stark R.M. Central acetabular fractures Journal of Bone and Joint Surgery 64-A 4 695 714 1964
- Judet, R. Judet, J. Letournel, E. Fractures of the acetabulum: Classification and surgical approaches for open reduction Journal of Bone and Joint Surgery 46-A 8 1615 1646 1964
- Strother et al. Injury and intrusion in side impacts and rollovers Society of Automotive Engineers SAE # 840403 1984
- Viano, D.C. Lau, I.V. Asbury, C. Biomechanics of the human chest, abdomen, and pelvis in lateral impact Society of Automotive Engineers SAE #896113 1989
- Cavanaugh, J.M. Walilko, T.J. Malhotra, A. Zhu, Y. King, A.I. Biomechanical response and injury tolerance of the pelvis in twelve sled side impacts Society of Automotive Engineers SAE # 902305 1990
- Heeg, M. Klasen, H.J. Visser, J.D. Operative treatment for acetabular fractures Journal of Bone and Joint Surgery 72B 3 383 386 1990
- Hofmann, A.A. Dahl, C.P. Wyatt, R.W.B. Experience with acetabular fractures Journal of Trauma 24 8 750 752 1980
- Pennel, G.F. Davidson, J Garside, H. Plews, J. Results of treatment of acetabular fractures Clin Orthop 151 115 123 1980
- Walker, P.S. Human joints and their artificial replacements Charles C. Thomas Springfield, Illinois 55 1977
- Plummer, J.W. Bidez, M.W. Alonso, J. Parametric finite element studies of the human pelvis: The influence of load magnitude and duration on pelvic tolerance during side impact Society of Automotive Engineers SAE # 962411 1996
- Cesari, D. Ramet, M. Pelvic tolerance and protection criteria in side impact Society of Automotive Engineers SAE # 821159 1982
- Cesari, D. Ramet, M. Bouquet, R. Tolerance of human pelvis to fracture and proposed pelvic protection criterion to be measured on side impact dummies Society of Automotive Engineers SAE #826036 1982
- Cesari, D. Ramet, M. Clair, P. Evaluation of pelvic fracture tolerance in side impact Society of Automotive Engineers SAE # 801306 1980
- Zhu, J.Y. Cavanaugh, M. King, A.I. Pelvic biomechanical response and padding benefits in side impact based on a cadaveric test series Society of Automotive Engineers SAE # 933128 1993
- King, A.I. Viano, D.C. Mizeres, N. States, J.D. Humanitarian benefits of cadaver research on injury prevention The Journal of Trauma: Injury, Infection, and Critical Care 38 4 564 569 1995
- Eppinger, R.H. Marcus, J.H. Morgan, R.M. Development of dummy and injury index for NHTSA's thoracic side impact protection research program Society of Automotive Engineers SAE # 840885 1984
- Nusholtz, G.S. Kaiker, P.S. Pelvic Stress Journal of Biomechanics 19 12 1003 1014 1986