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Neurophysiology of Joints
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
Håkan Johansson, Per Sjölander
Much work remains to be done concerning the population densities of different receptor categories in ligaments other than the knee joint ligaments. Yet Golgi tendon organlike endings seem to be present in all extrinsic and intrinsic ligaments (2,3,5,13,17,18,28–33,53,55), with the possible exception of some joints. Unlike Golgi and free nerve endings, Ruffini and Pacinian endings have not been identified in all investigated ligaments outside the knee joint. However, there are indications that the occurrence of these receptors in ligaments may follow the same “rule” as their occurrence in capsules. That is, Ruffini endings are more common in proximal joints and Pacinian corpuscles are more common in distal joints. Thus, Pacinian corpuscles are common in the collateral and palmar ligaments of the metacarpophalangealjoint, Ruffini endings are absent in the collateral ligaments and few in the palmar ligament (46). In the knee joint, ligaments with both Ruffini and Pacini endings seem to be fairly common. Even though free nerve endings seem to be presentin all ligaments (5,17,18,30,31,33,49,65), there might be differences in density between various ligaments. For example, among the ligaments of the vertebral column, free nerve endings are most densely distributed in the posterior longitudinal ligament, less densely in the anterior longitudinal ligament, and very sparsely in the interspinous and naval ligaments (5,77).
The Thoracolumbar Spine
Published in Melanie Franklyn, Peter Vee Sin Lee, Military Injury Biomechanics, 2017
Brian D. Stemper, Narayan Yoganandan, Frank A. Pintar
Although other fractures occurred, some of the fracture types common to multiple specimens are discussed in more detail here. Fracture types can be defined according to the three-column concept, as described by Denis (Denis 1984), wherein the anterior column consists of the anterior vertebral body, anterior intervertebral disc and anterior longitudinal ligament, the middle column consists of the posterior vertebral body, the posterior intervertebral disc and the posterior longitudinal ligament, and the posterior column consists of the posterior ligamentous complex including the pedicles, facet joints, laminae and spinous processes (discussed further in Chapter 12). Due to the involvement of anterior and posterior columns or the middle column, these injuries can be attributed to axial compression. Vertical fractures affecting the anterior or posterior cortex were sustained at L2 and L3 by specimens subjected to the most severe acceleration pulses, as shown in Figure 13.5. Those fractures occurred in the caudal-cranial direction at approximately 1/3 the anterior–posterior body depth from the anterior or posterior cortex and involved the anterior/posterior cortex and cranial endplate, although integrity of the caudal endplate was not affected. One of those specimens also sustained a longitudinal fracture through the lamina and proximal aspect of the spinous process, and also affecting the pars interarticularis (Figure 13.5, right).
Spine
Published in David A Lisle, Imaging for Students, 2012
As well as diagnosing and classifying cervical spine injuries, it is important to decide whether the injury is stable or not. Instability implies the possibility of increased spinal deformity or neurological damage occurring with mobilization or continued stress. Viewed laterally, the spine may be divided into three columns:Anterior: anterior two-thirds of the vertebral bodyMiddle: posterior one-third of vertebral body and posterior longitudinal ligamentPosterior: facet joints and bony arch of spinal canal (pedicles, laminae and spinous process).
Analysis of stress and stabilization in adolescent with osteoporotic idiopathic scoliosis: finite element method
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Qiaolin Zhang, Yan Zhang, Teo. Ee Chon, Julien S. Baker, Yaodong Gu
Ligaments play an important role in the biomechanics of the spine because they provide stability to the joints during rest and movement. In this work, we considered the seven most important ligaments in the lumbar spine, as shown below. They are: posterior longitudinal ligament, anterior longitudinal ligament, transverse ligament, ligamentum flavum, capsular ligament, supraspinous ligament and intraspinous ligament. Ligaments restrict the movement of lumbar vertebrae by stretching cones. In Ansys Workbench 19.0 (ANSYS, Inc., Canonsburg, United States), we use springs to simulate the tension of ligaments. We insert the spring on the surface of the cone according to the anatomical structure, as shown in Figure 4. The ligament structure of spinal functional units is stimulated by linear tension springs, which is defined as：
Finite element mechanics analysis of lumbar spine with normal and varying degrees of herniated lesions under different working conditions and material properties
Published in Mechanics of Advanced Materials and Structures, 2022
Yu Hui, Ze-xun Zhou, Jing Du, Bo Wu, Wei Huang
Through observation, it can be seen that under various working conditions of the normal model, the compressive stress of the facet joints under lateral bending is basically larger, followed by flexion and extension. When the left or right sides of the spine are bent, the compressive stress of the opposite facet joint will increase, which is consistent with the clinical manifestations. From the comparison of the compressive stress of the facet joints in flexion and extension states, we can find that the compressive stress of the facet joints in the flexion state is larger and stress distribution is wider. It can be interpreted as: When the vertebra body is doing forward flexion, it is pulled by the ligaments of the posterior longitudinal ligament, supraspina, interspinous, and ligamentum flavum. In the spatial position, the vertebral body approximately takes the bone facet joint as the support point, and rotates in the longitudinal direction; the extension movement is mainly only affected by the traction of the anterior longitudinal ligament, and the compressive stress of the facet joint as the support point is smaller than that of the flexion state.
Biomechanical modeling of spinal ligaments: finite element analysis of L4-L5 spinal segment
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Shabnam Hamidrad, Masoud Abdollahi, Vahid Badali, Mohammad Nikkhoo, Sadegh Naserkhaki
Ligaments included anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), capsular ligament (CL), intertransverse ligament (ITL), ligamentum flavum (LF), supraspinous ligament (SSL), and interspinous ligament (ISL). Four different approaches were utilized to model the ligaments resulting in four different models as summarized in Table 2 and depicted in Figure 1. Uniaxial truss elements were used in three of the models and 2 D shell element was used in one of them. In the 3 D model, space trusses were structured in longitudinal, anteroposterior, mediolateral and diagonal directions which were connected together in space joints three dimensionally (Figure 1(d)). Initially two layers of parallel longitudinal trusses were constructed between two vertebrae at the position of each ligament. Then, they were divided to approximately 1 mm elements. Finally, diagonal and transverse elements were generated between every two adjacent joints of these elements.