Related Experiment Video
Updated: Jul 15, 2026
04:46
Rat Model of Adhesive Capsulitis of the Shoulder
Published on: September 28, 2018
Human Cervical Motion Segment Flexibility and Facet Capsular Ligament Strain under Combined Posterior Shear,
G P Siegmund1, B S Myers, M B Davis
1University of British Columbia, MacInnis Engineering Associates.
Stapp Car Crash Journal
|April 27, 2007
Summary
Cervical facet capsular ligaments may be injured during whiplash. This study quantified ligament strain under simulated whiplash loading, suggesting injury potential from combined forces in rear-end impacts.
Area of Science:
- Biomechanics
- Orthopedics
- Anatomy
Background:
- Cervical facet capsular ligaments are implicated in whiplash injuries.
- The precise injury mechanism within these ligaments during whiplash remains poorly understood.
Purpose of the Study:
- To quantify intervertebral flexibility and facet capsular ligament strain.
- To simulate whiplash-like loading conditions involving shear, bending, and compression.
Main Methods:
- Used two cervical motion segments (C3-4, C5-6) from seven female donors.
- Applied quasi-static posterior shear loads under varying axial preloads (0-325 N).
- Measured vertebral motion and facet capsular ligament strain using stereophotogrammetry.
Main Results:
- Neither flexibility nor maximum principal strain in the facet capsular ligament varied significantly with axial compression.
- Ligament strain reached 61% of failure strain levels.
- Two specimens experienced strains exceeding failure levels during flexibility tests.
Conclusions:
- Cervical facet capsular ligaments may be injured by combined shear, bending, and compression forces.
- These forces are relevant to loading conditions experienced during rear-end impacts.
- The study provides biomechanical insights into potential whiplash injury mechanisms.
Related Concept Videos
01:20Normal Strain under Axial Loading
Normal strain under axial loading is an important concept in the field of mechanics of materials. Axial loading implies the application of a force along the axis of a material, like a column or bar. This force can either compress or stretch the material. In the context of axial loading, normal strain is the deformation experienced by the material in the direction of the loading force. It's calculated as the change in length divided by the original length of the material. This unitless ratio...
01:12General Case of Eccentric Axial Loading
Unsymmetrical bending occurs when the bending moment applied to a structural member does not align with its principal axis. This misalignment leads to complex stress distributions and deflection patterns that differ from symmetrical bending, which are essential for designing structures to withstand different loading conditions.
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical bending,...
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical bending,...
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
01:16Eccentric Axial Loading in a Plane of Symmetry
Eccentric axial loading occurs when an axial load is applied away from the centroidal axis of a structural member. This scenario is common in engineering, where structural elements may not be directly aligned due to various design or functional requirements.
01:11Deformation of Member under Multiple Loadings
When a rod is made of different materials or has various cross-sections, it must be divided into parts that meet the necessary conditions for determining the deformation. These parts are each characterized by their internal force, cross-sectional area, length, and modulus of elasticity. These parameters are then used to compute the deformation of the entire rod.
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
01:17Structural Joints: Cartilaginous Joints
As the name indicates, at a cartilaginous joint, the adjacent bones are united by cartilage, a tough but flexible type of connective tissue. Unlike synovial joints, these types of joints lack a joint cavity and involve bones joined together by either hyaline cartilage or fibrocartilage.
There are two types of cartilaginous joints:
Synchondrosis
A synchondrosis ("joined by cartilage") is a cartilaginous joint where bones are connected by hyaline cartilage. Synchondrosis may be temporary or...
There are two types of cartilaginous joints:
Synchondrosis
A synchondrosis ("joined by cartilage") is a cartilaginous joint where bones are connected by hyaline cartilage. Synchondrosis may be temporary or...