Finite Element Analysis of the Effects of Head-Supported Mass on Neck Responses: Complete Phase Three Report

Affiliations

¹Royal Institute of Technology, School of Technology and Health, Division of Neuronic Engineering Stockholm, Sweden

Links

URL: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA456789

Abstract and keywords

Technical Objectives: The objectives for the whole project were to:

determine the relationships between head supported mass and the risk of neck injuries. The results should be used in a Graphical user interface. In this phase three report has also the Graphical User Interphase (GUI) been evaluated and the question about the how the muscle activation affect the injury risk.
II. to develop and implement a 3D numerical muscle model.

Method: Ad. I was done using a detailed Finite Element (FE) model of the human neck developed at the Royal Institute of Technology, Stockholm, Sweden. Ad. II was based on an FE model with a new geometry of the cervical spine.

I. The simulation matrix included seven impact situations (frontal, rear end, lateral, vertical, and oblique impacts in the horizontal plane, frontal plane, and sagittal plane.), three impact severities (5, 13.5 and 22 G), three helmet masses (1, 2 and 3 kg), and nine locations of the Center of Gravity of the helmet (offset relative to the CG of the head with -2, 0, 2, 4 and 6 cm in the superior/inferior and anterior/posterior directions). The neck model with just enough muscle activation to keep the head and helmet in upright position was compared with the model set to 100% activation of the neck muscle force. The GUI was evaluated using helmet inertial properties from two real helmets in use by the US Army.
II. The Suboccipital muscles, Deep dorsal muscles, Ventral muscles, Muscles linking the skull with the shoulder girdle and the Muscles linking the vertebral column with the scapulas and the ribcage have been modeled using 4 node solid elements for the passive properties and spring elements for the active part. The surfaces defining the muscles in the cervical spine were detected by segmentation from MR-scans using the software AMIRA. The surfaces were then smoothed and adjusted using the software Hypermesh. The meshing of the muscles was then performed with the software Truegrid. Contacts were defined between the interacting muscles. The new muscle model has been compared to a model with a spring muscle model for both the passive and the active part.

Results:

I. The KTH neck model has successfully been used to generate results for the GUI. Results from all simulations have been reported and sent to Titan Corporation that is contracted by USAARL to program the GUI. The GUI that uses an interpolation method to calculate the neck injury risk for a general helmet with a user defined HSM configuration shows to give realistic interpolated values compared to the FE model of the neck.
II. The 3D muscle model for the cervical spine includes 22 pairs of muscles. The solid muscle model showed to stabilize the vertebral column better than the spring muscle model. The model is still under evaluation and need further validation to be used in the HSM evaluation project.

Keywords: Finite element analysis; cervical spine; injury; prevention; muscles

Cited Works (16)

Year	Entry
2002	van der Horst MJ. Human Head Neck Response in Frontal, Lateral and Rear End Impact Loading: Modelling and Validation [PhD thesis]. Eindhoven, The Netherlans: Technische Universiteit Eindhoven; 2002.
1993	Best TM. A Biomechanical Study of Skeletal Muscle Strain Injuries [PhD thesis]. Duke University; 1993.
1988	Myklebust JB, Pintar F, Yoganandan N, Cusick JF, Maiman D, Myers TJ, Sances A Jr. Tensile strength of spinal ligaments. Spine. May 1988;13(5):528-531.
1978	Ewing CL, Thomas DJ, Lustick L, Muzzy WH III, Willems GC, Majewski P. Effect of initial position on the human head and neck response to +Y impact acceleration. In: Proceedings of the 22nd Stapp Car Crash Conference. October 24-26, 1978; Ann Arobor, MI. Warrendale, PA: Society of Automotive Engineers:103-138. SAE 780888.
1998	Vasavada AN, Li S, Delp SL. Influence of muscle morphometry and moment arms on the moment-generating capacity of human neck muscles. Spine. February 15, 1998;23(4):412-422.
1989	Yoganandan N, Pintar F, Butler J, Reinartz J, Sances A Jr, Larson SJ. Dynamic response of human cervical spine ligaments. Spine. October 1989;14(10):1102-1110.
2005	Brolin K, Halldin P, Leijonhufvud I. The effect of muscle activation on neck response. Traffic Inj Prev. March 2005;6(1):67-76.
2004	Currey JD. Tensile yield in compact bone is determined by strain, post-yield behaviour by mineral content. J Biomech. April 2004;37(4):549-556.
2005	Anderson J, Hsu A, Vasavada A. Morphology, architecture, and biomechanics of human cervical multifidus. Spine. February 15, 2005;30(4):E86-E91.
1995	Myers BS, Van Ee CA, Camacho DLA, Woolley CT, Best TM. On the structural and material properties of mammalian skeletal muscle and its relevance to human cervical impact dynamics. In: Proceedings of the 39th Stapp Car Crash Conference. November 8-10, 1995; San Diego, CA. Warrendale, PA: Society of Automotive Engineers:203-214. SAE 952723.
1997	Ashrafiuon H, Alem NM, McEntire BJ. Effects of weight and center of gravity location of head-supported devices on neck loading. Aviat Space Environ Med. October 1997;68(10):915-922.
2002	Kleiven S. Finite Element Modeling of the Human Head [PhD thesis]. Stockholm, Sweden: Royal Institute of Technology; 2002.
1998	Kamibayashi LK, Richmond FJR. Morphometry of human neck muscles. Spine. June 15, 1998;23(12):1314-1323.
2003	Chancey VC, Nightingale RW, Van Ee CA, Knaub KE, Myers BS. 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. 2003;47:135-153. SAE 2003-22-0008.
1976	Ewing CL, Thomas DJ, Lustick L, Muzzy WH, Willems G, Majewski PL. The effect of duration, rate of onset, and peak sled acceleration on the dynamic response of the human head and neck. In: Proceedings of the 20th Stapp Car Crash Conference. October 18-20, 1976; Dearborn, MI. Warrendale, PA: Society of Automotive Engineers:3-41. SAE 760800.
1988	Winters JM, Stark L. Estimated mechanical properties of synergistic muscles involved in movements of a variety of human joints. J Biomech. 1988;21(12):1027-1041.

Cited By (1)

Year	Entry
2018	Schoenfeld M. Cervical Intervertebral Kinematics and Neck Muscle Responses During Simulated Vehicle Rollovers [Master's thesis]. Vancouver, BC: University of British Columbia; August 2018.