scholarly journals A three-dimensional multibody computational model of lumbar spine

Author(s):  
Roozbeh Seradj Zadeh

The lower back is the most sensitive part of the human spine and over loading and bad posture during lifting can damage this area of the body. The lumbar spine consists of five vertebrae, which are responsible for carrying the weight of the upper body and loads. Intervertebral discs allow articulation between vertebrae. These discs are primarily made of non-homogeneous soft tissue, which allows the vertebrae to move and flex in all directions. Biomechanical models have been developed in the past decades to model and to predict the behavior of the spine in response to different loads. With the advances in computer modeling technology, analytical methods have become more popular in modeling the spine. These models are more cost effective and practical compared to the early models and use of human volunteers and cadavers. Unfortunately due to the complexity of the spine, most of the models failed to offer an accurate estimation of reaction moments and forces. Most models also use proprietary and custom-made software which makes it difficult for other researchers to use and modify them. This thesis reports the development and verification of a multi-body computational model of the lumbar spine. The model comprises five lumbar vertebrae (L1 to L5) and pelvis (S1). The vertebrae are connected to each other by invertebral discs, which consist of an anatomically correct kinematic and dynamic constraints. This combination represents a six degree-of-freedom mobility and enables the model to accommodate flexion, lateral bending, and axial rotation. The model is validated by carrying out a series of case studies including experimental motion studies. It is also used for preliminary evaluation of an ergonomical device called the dynamic trunk support (DTS), developed at Ryerson, School of Occupational and Public Health, in conjunction with the Mechanical and Industrial Engineering department. The results are in good agreement with the experimental results.

2021 ◽  
Author(s):  
Roozbeh Seradj Zadeh

The lower back is the most sensitive part of the human spine and over loading and bad posture during lifting can damage this area of the body. The lumbar spine consists of five vertebrae, which are responsible for carrying the weight of the upper body and loads. Intervertebral discs allow articulation between vertebrae. These discs are primarily made of non-homogeneous soft tissue, which allows the vertebrae to move and flex in all directions. Biomechanical models have been developed in the past decades to model and to predict the behavior of the spine in response to different loads. With the advances in computer modeling technology, analytical methods have become more popular in modeling the spine. These models are more cost effective and practical compared to the early models and use of human volunteers and cadavers. Unfortunately due to the complexity of the spine, most of the models failed to offer an accurate estimation of reaction moments and forces. Most models also use proprietary and custom-made software which makes it difficult for other researchers to use and modify them. This thesis reports the development and verification of a multi-body computational model of the lumbar spine. The model comprises five lumbar vertebrae (L1 to L5) and pelvis (S1). The vertebrae are connected to each other by invertebral discs, which consist of an anatomically correct kinematic and dynamic constraints. This combination represents a six degree-of-freedom mobility and enables the model to accommodate flexion, lateral bending, and axial rotation. The model is validated by carrying out a series of case studies including experimental motion studies. It is also used for preliminary evaluation of an ergonomical device called the dynamic trunk support (DTS), developed at Ryerson, School of Occupational and Public Health, in conjunction with the Mechanical and Industrial Engineering department. The results are in good agreement with the experimental results.


2016 ◽  
Vol 17 (2) ◽  
pp. 138-141
Author(s):  
Samira Sharmin ◽  
Mabubul Haque ◽  
Syedur Rahman Miah ◽  
Md Mahbub Ur Rahman ◽  
Jasmine Ara Haque ◽  
...  

Objectives: Low bone mass is a common disorder in elderly population which predisposes to fracture with minimal trauma. This study was performed to find out the association between the Body Mass Index (BMI) and Bone Mineral Density (BMD) in postmenopausal women.Materials and Methods: This cross sectional study was carried out at Institute of Nuclear Medicine and Allied Sciences Comilla and Mitford, Dhaka over a period of 12 months from January 2013 to December 2013. A total 93 postmenopausal women were enrolled for this study. All postmenopausal women underwent a BMD scan of femoral neck and lumbar vertebrae using a Dual Energy X-ray Absorptiometry (DEXA). Participants were categorized into three groups according to their age and BMI. BMD were expressed base on T-score according to WHO criteria. The relation among BMI, age and BMD were assessed.Results: The results of this study showed that the mean age of the study group was 57.13±7.49 years with range of 46 to 75 years. The most postmenopausal women were in age group 55-65years. The mean BMI of the study subjects were 24.18±5.08 kg/m2 with a range of 15.62 to 36.20 kg/m2. Among 93 subjects osteopenia was greater at lumbar spine (45.2%) with T-score mean±SD-1.83±0.33 and osteoporosis at femoral neck (51.6%) with T-score mean ±SD-3.36±-0.67. Pearson’s correlation coefficient test showed inverse relationship between age and BMD both lumbar spine (r = -0.301, p = 0.003) and femoral neck (r = -0.303, p=0.003) whereas the positive relation between BMI and BMD both at lumbar spine (r=0.338, p=0.001) and femoral neck (r =0.343, p=0.001). These showed that with advancing age, BMD decreases and the risk of osteoporosis increases and with increasing BMI, BMD increases and risk of osteoporosis decreases.Conclusion: The findings of this study portrait that aging and low BMI are risk factors associated with bone loss. So preventive measure should be taken for high risk post menopausal women.Bangladesh J. Nuclear Med. 17(2): 138-141, July 2014


Author(s):  
Martin E. Atkinson

The locomotor system comprises the skeleton, composed principally of bone and cartilage, the joints between them, and the muscles which move bones at joints. The skeleton forms a supporting framework for the body and provides the levers to which the muscles are attached to produce movement of parts of the body in relation to each other or movement of the body as a whole in relation to its environment. The skeleton also plays a crucial role in the protection of internal organs. The skeleton is shown in outline in Figure 2.1A. The skull, vertebral column, and ribs together constitute the axial skeleton. This forms, as its name implies, the axis of the body. The skull houses and protects the brain and the eyes and ears; the anatomy of the skull is absolutely fundamental to the understanding of the structure of the head and is covered in detail in Section 4. The vertebral column surrounds and protects the spinal cord which is enclosed in the spinal canal formed by a large central canal in each vertebra. The vertebral column is formed from 33 individual bones although some of these become fused together. The vertebral column and its component bones are shown from the side in Figure 2.1B. There are seven cervical vertebrae in the neck, twelve thoracic vertebrae in the posterior wall of the thorax, five lumbar vertebrae in the small of the back, five fused sacral vertebrae in the pelvis, and four coccygeal vertebrae—the vestigial remnants of a tail. Intervertebral discs separate individual vertebrae from each other and act as a cushion between the adjacent bones; the discs are absent from the fused sacral vertebrae. The cervical vertebrae are small and very mobile, allowing an extensive range of neck movements and hence changes in head position. The first two cervical vertebrae, the atlas and axis, have unusual shapes and specialized joints that allow nodding and shaking movements of the head on the neck. The thoracic vertebrae are relatively immobile. combination of thoracic vertebral column, ribs, and sternum form the thoracic cage that protects the thoracic organs, the heart, and lungs and is intimately involved in ventilation (breathing).


2019 ◽  
Vol 25 (1) ◽  
pp. 68-76
Author(s):  
V.P. Danylevych ◽  
Yu.Y. Guminskyi ◽  
V.O. Tykholaz ◽  
Y.O. Bezsmertnyi ◽  
S.V. Pavlov ◽  
...  

In nowadays, an important area in medicine is the early preclinical identification of the parameters deviations from the norm, where mathematical modeling can help, which should be used to calculate individual linear parameters of internal structures based on external parameters of the body. The aim of the study was to calculate the individual total linear measures of the lumbar intervertebral discs in juniors and men of the first adulthood (17-28 years) in norm. The total size of the each intervertebral discs were calculated a sum of the anterior-posterior diameter, frontal diameter and vertical sizes of each lumbar intervertebral discs, which were measured by MRI. The next step was to calculate the relative proportional nonlinear somato-disc rates (based on body weight and body length) for each individual examined. Mathematical processing of the measured parameters and the relative values of the somato-disc relationships was carried out by the statistical data processing program “STATISTICA 6.1” using parametric methods. The correct distribution of the variational series indicators, mean values and their standard errors were evaluated. Based on relative values the mathematical model was created to obtain individual values of the TS of the lumbar intervertebral discs. Subsequently, we compared the measured total discs sizes of the anterior-posterior, frontal diameters and vertical sizes of the lumbar intervertebral discs with a mathematically calculated value for each lumbar intervertebral discs. The significant difference between the mathematically calculated and measured values of the total intervertebral discs’ sizes of the didn’t exceed 10%. Determination of the standard linear dimensions of the intervertebral discs of the lumbar spine using CT and MRI and comparison with theoretically calculated indices will make it possible to diagnose early manifestations of the lumbar intervertebral discs pathology.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Ameet K. Aiyangar ◽  
Liying Zheng ◽  
Scott Tashman ◽  
William J. Anderst ◽  
Xudong Zhang

Availability of accurate three-dimensional (3D) kinematics of lumbar vertebrae is necessary to understand normal and pathological biomechanics of the lumbar spine. Due to the technical challenges of imaging the lumbar spine motion in vivo, it has been difficult to obtain comprehensive, 3D lumbar kinematics during dynamic functional tasks. The present study demonstrates a recently developed technique to acquire true 3D lumbar vertebral kinematics, in vivo, during a functional load-lifting task. The technique uses a high-speed dynamic stereo-radiography (DSX) system coupled with a volumetric model-based bone tracking procedure. Eight asymptomatic male participants performed weight-lifting tasks, while dynamic X-ray images of their lumbar spines were acquired at 30 fps. A custom-designed radiation attenuator reduced the radiation white-out effect and enhanced the image quality. High resolution CT scans of participants' lumbar spines were obtained to create 3D bone models, which were used to track the X-ray images via a volumetric bone tracking procedure. Continuous 3D intervertebral kinematics from the second lumbar vertebra (L2) to the sacrum (S1) were derived. Results revealed motions occurring simultaneously in all the segments. Differences in contributions to overall lumbar motion from individual segments, particularly L2–L3, L3–L4, and L4–L5, were not statistically significant. However, a reduced contribution from the L5–S1 segment was observed. Segmental extension was nominally linear in the middle range (20%–80%) of motion during the lifting task, but exhibited nonlinear behavior at the beginning and end of the motion. L5–S1 extension exhibited the greatest nonlinearity and variability across participants. Substantial AP translations occurred in all segments (5.0 ± 0.3 mm) and exhibited more scatter and deviation from a nominally linear path compared to segmental extension. Maximum out-of-plane rotations (<1.91 deg) and translations (<0.94 mm) were small compared to the dominant motion in the sagittal plane. The demonstrated success in capturing continuous 3D in vivo lumbar intervertebral kinematics during functional tasks affords the possibility to create a baseline data set for evaluating the lumbar spinal function. The technique can be used to address the gaps in knowledge of lumbar kinematics, to improve the accuracy of the kinematic input into biomechanical models, and to support development of new disk replacement designs more closely replicating the natural lumbar biomechanics.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Abdelmonem A. Hegazy ◽  
Raafat A. Hegazy

Despite the increasing recognition of the functional and clinical importance of lumbar lordosis, little is known about its description, particularly in Egypt. At the same time, magnetic resonance imaging (MRI) has been introduced as a noninvasive diagnostic technique. The aim of this study was to investigate the anatomy of the lumbar lordosis using midsagittal MRIs. Normal lumbar spine MRIs obtained from 93 individuals (46 males, 47 females; 25–57 years old) were evaluated retrospectively. The lumbar spine curvature and its segments “vertebrae and discs” were described and measured. The lumbar lordosis angle (LLA) was larger in females than in males. Its mean values increased by age. The lumbar height (LH) was longer in males than in females. At the same time, the lumbar breadth (LB) was higher in females than in males. Lumbar index (LI = LB/LH × 100) showed significant gender differences (P<0.0001). Lordosis was formed by wedging of intervertebral discs and bodies of lower lumbar vertebrae. In conclusion, MRI might clearly reveal the anatomy of the lumbar lordosis. Use of LI in association with LLA could be useful in evaluation of lumbar lordosis.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Rizvan Ya Abdullaiev ◽  
Ilgar G Mammadov ◽  
Tatyana A Dudnik ◽  
Roman R Abdullaiev

Objective: To improve the efficiency of lumbar intervertebral discs protrusion by determining the ultrasound biomarkers. Materials and Methods: The study included 68 patients with the disc protrusion and 65 healthy adolescents with normal lumbar intervertebral discs and neurologic status aged 16-18 years. Ultrasonography (USG) was performed at the level of disks L1-L2, L2-L3, L3-L4, L4-L5, L5-S1 in longitudinal and transverse projections. In longitudinal section was measured height of lumbar vertebrae and intervertebral discs, in axial section – the sagittal sizes of intervertebral discs and spinal canal, width of spinal nerve canals, thickness of the yellow ligament. Results: In 31 (45,6±6,0%) cases the protrusion was paramedian, in 16 (23,5±5,1%) – posterolateral, in 13 (19,1±4,8) – median and in 8 (11,8±3,9%) – circular types. The paramedian protrusion was significantly more frequently recorded than the posterolateral (P<0,05), median and circular (p <0.001) types. In 7 (10,3±3,7% ) cases the protrusion was localized at the level of L2-L3, in 13 (19,1 ±4,8%) – L3-L4, in 27 (39,7±5,9%) - at the level of L4-L5 and in 21 (30,9±5,6%) – at the level of L5-S1 respectively. There were no significant differences in the frequency of occurrence between L2-L3 and L3-L4, as well as L4-L5 and L5-S1. The lower located lumbar discs were significantly more affected than the upper ones (P<0,05; P<0,001).Conclusions: In adolescents in the lumbar spine, paramedian protrusion are most commonly found, which are most often localized at the level of both L4-L5 and L5-S1. The greatest  narrowing and deformation of the spinal nerve canal is observed by posterolateral and paramedian protrusion. The greatest thickness of the yellow ligament, radiculopathy  is observed at level of L5-S1 protrusion. 


2020 ◽  
Vol 37 (6) ◽  
pp. 387-392
Author(s):  
Álvaro Bustamante-Sánchez ◽  
Juan J Salinero ◽  
Juan Del Coso

ntroduction: Upper body injuries are less common than lower body injuries in basketball, but there is still a lack of knowled-ge about the relationship among their occurrence and the performance profile of professional basketball players. This study aimed to analyse the relationships between upper-body injuries and Key Performance Indicators (KPIs) of basketball players. Material and method: Statistical variables of 554 professional basketball players (age: 26.97±4.86 years, height: 199.23±8.80 cm, minutes per season: 441.18±301.41) in Spanish ACB (Asociación de Clubes de Baloncesto) professional competition were analysed for two seasons (2012-13 and 2013-14). Besided, injury reports were registered and injuries were categorized with OSICS-10 classification. The players who played the most minutes during the season were more likely to suffer lumbar spine, head, wrist, and hand injuries. The players injured in the thoracic spine obtained a better average in steals per minute. The players injured in the head or the elbow had better +/- performance per minute. The players injured in the neck had better means per minute in received fouls, free throws made and attempted. Results: The players injured in the lumbar spine had better means, per minute played, in assists, probably by their continuous column twists to protect the ball with the body to avoid bumps. Players injured in the shoulder had more blocked shots per minute than those not injured, probably because the realization of a block involves a shoulder flexion and rotation. It would be interesting to carry out a specific follow-up in this type of player, for this type of injury. This information could be helpful to improve injury prevention with the use of KPIs of basketball.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Myoung Hoon Jung ◽  
Kak Namkoong ◽  
Yeolho Lee ◽  
Young Jun Koh ◽  
Kunsun Eom ◽  
...  

AbstractBioelectrical impedance analysis (BIA) is used to analyze human body composition by applying a small alternating current through the body and measuring the impedance. The smaller the electrode of a BIA device, the larger the impedance measurement error due to the contact resistance between the electrode and human skin. Therefore, most commercial BIA devices utilize electrodes that are large enough (i.e., 4 × 1400 mm2) to counteract the contact resistance effect. We propose a novel method of compensating for contact resistance by performing 4-point and 2-point measurements alternately such that body impedance can be accurately estimated even with considerably smaller electrodes (outer electrodes: 68 mm2; inner electrodes: 128 mm2). Additionally, we report the use of a wrist-wearable BIA device with single-finger contact measurement and clinical test results from 203 participants at Seoul St. Mary’s Hospital. The correlation coefficient and standard error of estimate of percentage body fat were 0.899 and 3.76%, respectively, in comparison with dual-energy X-ray absorptiometry. This result exceeds the performance level of the commercial upper-body portable body fat analyzer (Omron HBF-306). With a measurement time of 7 s, this sensor technology is expected to provide a new possibility of a wearable bioelectrical impedance analyzer, toward obesity management.


2021 ◽  
pp. 004051752110001
Author(s):  
Pengpeng Cheng ◽  
Xianyi Zeng ◽  
Pascal Bruniaux ◽  
Jianping Wang ◽  
Daoling Chen

To study the upper body characteristics of young men, the body circumference, length, width, thickness, and angle of young men aged 18–25 and 26–35 years were collected to comprehensively characterize the concave and convex features of the front, back, and side of the human body. The Cuckoo Search-Density Peak intelligent algorithm was used to extract the feature factors of the upper body of men, and to cluster them. To verify the effectiveness of the intelligent algorithm, the clustering results of Cuckoo Search-Density Peak, Density Peak, Particle Swarm Optimization-Density Peak algorithm, Ant Colony Optimization-Density Peak algorithm, Genetic Algorithm-Density Peak algorithm, and Artificial Bee Colony-Density Peak algorithm were evaluated by Silouette and F-measures, respectively. The results show that the Cuckoo Search-Density Peak algorithm has the best clustering results and is superior to other algorithms. There are some differences in somatotype characteristics and somatotype indexes between young men aged 18–25 and 26–35 years.


Sign in / Sign up

Export Citation Format

Share Document