Project Card 04

Finite Element Simulation of Whiplash Injury and Neck Injury Criteria

Project Pathway

🟦 Numerical / Computational Modeling (FEM)

1. Background & Motivation

Whiplash-associated disorders (WAD) are among the most frequent injuries in low-speed rear-end vehicle collisions and remain a major challenge in trauma biomechanics. Despite extensive experimental and clinical research, whiplash injury mechanisms are still not fully understood, partly due to the complex anatomy and dynamic response of the cervical spine.

Finite element (FE) modeling provides a powerful framework for investigating cervical spine kinematics, load transmission, and neck injury criteria under whiplash loading conditions. Simplified FE models are widely used to study injury trends, compare injury criteria, and evaluate sensitivity to loading conditions.

This project focuses on developing and using a simplified FE model of the head-neck system to study whiplash injury mechanisms and compare commonly used neck injury criteria.

2. Core Biomechanical Question

How do whiplash loading conditions and modeling assumptions influence predicted neck injury metrics in a simplified finite element model of the cervical spine?

3. Injury Mechanisms & Relevant Injury Criteria

The project should address the following biomechanical aspects:

Whiplash injury mechanisms:
- Relative motion between head and torso
- Flexion-extension dynamics
- Shear forces and bending moments in the cervical spine
Early- and late-phase whiplash kinematics

Relevant neck injury criteria may include:

Neck Injury Criterion (NIC)
Nij criterion
Neck protection criterion (Nkm)
Upper/lower neck force-moment measures (conceptual discussion)

Students must justify the selection of injury criteria and explain their biomechanical meaning and limitations.

4. Modeling / Analysis Approach

This is a numerical FEM-based project using a simplified head-neck or cervical spine model.

The student is expected to:

Develop or adapt a simplified FE model of the head-neck system
Represent cervical vertebrae, intervertebral discs, and major ligaments at a conceptual level
Apply whiplash-relevant loading or kinematic boundary conditions
Compute and interpret neck injury metrics

High anatomical fidelity is not required. Emphasis is placed on mechanisms, trends, and interpretation.

5. Technical Specification (Core Section)

The project must include a clear description of:

a) Geometry and Model Structure

Level of anatomical detail (e.g., lumped segments, simplified vertebrae)
Modeling of head mass and inertia
Justification of simplifications

b) Material and Joint Modeling

Representation of discs and ligaments
Assumed stiffness, damping, or nonlinear behavior
Rationale for material parameter selection

c) Boundary Conditions and Loading

Whiplash loading scenario (e.g., imposed acceleration, velocity, or displacement)
Representation of torso support or seat interaction
Contact or coupling assumptions

d) Output Quantities

Head and neck kinematics
Forces and moments at relevant cervical levels
Computation of injury criteria (NIC, Nij, Nkm, etc.)

6. Parametric / Sensitivity Study

A limited parametric study is required, for example:

Variation of loading severity or pulse shape
Variation of neck stiffness or damping parameters
Comparison of different injury criteria responses

The focus should be on relative trends, not absolute injury thresholds.

7. Validation Strategy & Limitations

The project must explicitly discuss:

Comparison with published whiplash experiments or ATD data
Sensitivity of injury metrics to modeling assumptions
Limitations related to:
- simplified anatomy,
- lack of muscle activation modeling,
- absence of experimental validation

Students must clearly state which conclusions are justified by the model.

8. Feasibility & Computational Considerations

The project must address:

Software used (e.g., Abaqus/Explicit, LS-DYNA)
Computational cost and runtime
Time-step stability and numerical considerations
Reproducibility of simulations

Overly complex or computationally expensive models are discouraged.

9. Expected Outcomes

By the end of the project, the student should deliver:

A simplified FE model of whiplash loading
Computed neck injury metrics for selected scenarios
Sensitivity analysis results
A critical interpretation of whiplash injury predictions

The outcome should demonstrate numerical competence and biomechanical judgment.

10. Deliverables

Final Report (20-25 pages, excluding appendices)
Model description and representative figures
Injury metric plots and tables
Oral presentation (15-20 minutes)

Optional appendices:

Input files
Post-processing scripts
Additional simulation cases

11. Project-Specific Grading Rubric

Criterion	Description	Weight
Problem formulation & relevance	Clear definition of whiplash scenario and objectives	10%
Injury mechanism understanding	Correct interpretation of whiplash biomechanics	15%
Injury metric selection & justification	Appropriate and critical use of neck injury criteria	10%
FEM model formulation	Quality of geometry, joints, BCs, and assumptions	20%
Parametric / sensitivity analysis	Insightful exploration of trends and comparisons	15%
Validation & limitations	Realistic assessment of model credibility	15%
Technical clarity & professionalism	Quality of documentation and figures	15%
Total		100%

12. Project Scope Agreement

By choosing this project, the student agrees to:

Focus on mechanistic interpretation, not model complexity
Clearly document assumptions and limitations
Avoid overclaiming injury prediction accuracy

Note:
In whiplash biomechanics, understanding trends and mechanisms is often more valuable than predicting exact injury thresholds.