Three-dimensional Spine Research Articles

Analysis of three-dimensional spine growth for vertebral body tethering patients at 2 and 5years post operatively.

Scoliosis can be treated with vertebral body tethering (VBT) as a motion-sparing procedure. However, the knowledge of how growth is affected by a tether spanning multiple levels is unclear in the literature. Three-dimensional true spine length (3D-TSL) is a validated assessment technique that accounts for the shape of the spine in both the coronal and sagittal planes. This study aimed to assess if 3D-TSL increases over a five-year period after VBT implantation in thoracic curves for idiopathic scoliosis. Prospectively collected radiographic data from an international pediatric spine registry was analyzed. Complete radiographic data over three visits (post-operative, 2years, and 5years) was available for 53 patients who underwent VBT. The mean age at instrumentation of this cohort was 12.2 (9-15) years. The average number of vertebrae instrumented was 7.3 (SD 0.7). Maximum Cobb angles were 50° pre-op, which improved to 26° post-op (p < 0.001) and was maintained at 5years (30°; p = 0.543). Instrumented Cobb angle was 22° at 5years (p < 0.001 vs 5-year maximum Cobb angle). An accentuation was seen in global kyphosis from 29° pre-operative to 41° at 5years (p < 0.05).The global spine length (T1-S1 3D-TSL) started at 40.6cm; measured 42.8cm at 2years; and 44.0cm at the final visit (all p < 0.05). At 5years, patients reached an average T1-S1 length that is comparable to a normal population at maturity.Immediate mean post-operative instrumented 3D-TSL (top of UIV-top of LIV) was 13.8cm two-year length was 14.3cm; and five-year length was 14.6cm (all p < 0.05). The mean growth of 0.09cm per instrumented level at 2years was approximately 50% of normal thoracic growth.Patients who grew more than 0.5cm at 2years had a significantly lower BMI (17.0 vs 19.0, p < 0.05) and smaller pre-operative scoliosis (48° vs 53°, p < 0.05). Other subgroup analyses were not significant for age, skeletal maturity, Cobb angles or number of spanned vertebras as contributing factors. This series demonstrates that 3D-TSL increased significantly over the thoracic instrumented levels after VBT surgery for idiopathic scoliosis. This represented approximately 50% of expected normal thoracic growth over 2years.

Functional analysis of postural spinal and pelvic parameters using static and dynamic spinometry

BackgroundSpinometry is a radiation-free method to three-dimensional spine imaging that provides additional information about the functional gait patterns related to the pelvis and lower extremities. This radiation-free technology uses the surface topography of the trunk to analyze surface asymmetry and identify bony landmarks, thereby aiding the assessment of spinal deformity and supporting long-term treatment regimes. Especially reliable dynamic spinometric data for spine and pelvis are necessary to evaluate the management of non-specific back pain. Research aimThis study aims to generate reliable dynamic spinometric data for spine and pelvis parameters that can serve as reference data for future studies and clinical practice. MethodsThis study assessed 366 subjects (185 females) under static and 360 subjects (181 females) under dynamic (walking on a treadmill at 3 km/h and 5 km/h) conditions. The DIERS Formetric 4Dmotion® system uses stripes of light to detect the surface topography of the spine and pelvis and identifies specific landmarks to analyze the spine during standing and walking. ResultsRelevant gender effects were calculated for lordotic angle (ηp2 = 0.22) and pelvic inclination (ηp2 = 0.26). Under static conditions, female subjects showed larger values for both parameters (lordotic angle: 41.6 ± 8.60°; pelvic inclination: 25.5 ± 7.49°). Regarding speed effects, three relevant changes were observed (sagittal imbalance: ηp2 = 0.74, kyphotic angle: ηp2 = 0.13, apical deviation: ηp2 = 0.11). The most considerable changes were observed between static condition and 3 km/h, especially for sagittal imbalance and lordotic angle. For these parameters, relevant effect sizes (d > 0.8) were calculated between static and 3 km/h for males and females. Concerning clinical vertebral parameters, only lordotic angle and pelvic inclination were correlated with each other (r = 0.722). ConclusionThis study generated a gender-specific reference database of asymptomatic individuals for static and dynamic spinometry. It demonstrated that the DIERS Formetric 4Dmotion® system could capture natural changes in static and dynamic situations and catalogue functional adaptations of spino-pelvic statics at different speeds. The lordotic angle is an indirect marker of pelvic inclination, allowing spinometry to identify individuals at risk even under dynamic conditions.

Kinematic difference and asymmetries during level walking in adolescent patients with different types of mild scoliosis

BackgroundAdolescent idiopathic scoliosis (AIS), three-dimensional spine deformation, affects body motion. Previous research had indicated pathological gait patterns of AIS. However, the impact of the curve number on the walking mechanism has not been established. Therefore, this study aimed to compare the gait symmetry and kinematics in AIS patients with different curve numbers to healthy control.ResultsIn the spinal region, double curves AIS patients demonstrated a smaller sagittal symmetry angle (SA) and larger sagittal convex ROM of the trunk and lower spine than the control group. In the lower extremities, the single curve patients showed a significantly reduced SA of the knee joint in the frontal plane, while the double curves patients showed a significantly reduced SA of the hip in the transverse plane.ConclusionThe curve number indeed affects gait symmetry and kinematics in AIS patients. The double curves patients seemed to adopt a more "careful walking" strategy to compensate for the effect of spinal deformation on sensory integration deficits. This compensation mainly occurred in the sagittal plane. Compared to double curves patients, single curve patients unitized a similar walking strategy with healthy subjects.

Personal and Clinical Determinants of Brace-Wearing Time in Adolescents with Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS) is a three-dimensional spine and trunk deformity. Bracing is an effective treatment for medium-degree curves. Thermal sensors help monitor patients' adherence (compliance), a critical issue in bracing treatment. Some studies investigated adherence determinants but rarely through sensors or in highly adherent cohorts. We aimed to verify the influence of personal and clinical variables routinely registered by physicians on adherence to brace treatment in a large cohort of consecutive AIS patients from a highly adherent cohort. We performed a cross-sectional study of patients consecutively recruited in the last three years at a tertiary referral institute and treated with braces for one year. To ensure high adherence, for years, we have provided specific support to brace treatment through a series of cognitive-behavioural interventions for patients and parents. We used iButton thermal sensor systematic data collection to precisely analyse the real brace-wearing time. We included 514 adolescents, age 13.8 ± 1.6, with the worst scoliosis curve of 34.5 ± 10.3° Cobb. We found a 95% (95CI 60-101%) adherence to the brace prescription of 21.9 ± 1.7 h per day. Determinants included gender (91% vs. 84%; females vs. males) and age < 14 years (92% vs. 88%). Brace hours prescription, BMI, and all clinical variables (worst curve Cobb degrees, angle of trunk rotation, and TRACE index for aesthetics) did not influence adherence.

Three-dimensional spine reconstruction from biplane radiographs using convolutional neural networks

PurposeThe purpose of this study was to develop and evaluate a deep learning network for three-dimensional reconstruction of the spine from biplanar radiographs. MethodsThe proposed approach focused on extracting similar features and multiscale features of bone tissue in biplanar radiographs. Bone tissue features were reconstructed for feature representation across dimensions to generate three-dimensional volumes. The number of feature mappings was gradually reduced in the reconstruction to transform the high-dimensional features into the three-dimensional image domain. We produced and made eight public datasets to train and test the proposed network. Two evaluation metrics were proposed and combined with four classical evaluation metrics to measure the performance of the method. ResultsIn comparative experiments, the reconstruction results of this method achieved a Hausdorff distance of 1.85 mm, a surface overlap of 0.2 mm, a volume overlap of 0.9664, and an offset distance of only 0.21 mm from the vertebral body centroid. The results of this study indicate that the proposed method is reliable.

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Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional spine deformity with lateral curvature having a Cobb angle exceeding 10° in the individual. It affects about 1-4 percent of adolescents globally and more frequently occurs in females than males. Despite the extensive research carried out on AIS, its aetiology is not known yet. However, several genetic studies suggest the contribution of various genetic variants in the possible aetiology of AIS. This review summarises the genetic association studies, including linkage, candidate as well as genome-wide association studies that were carried out globally on AIS and also categorised the associated genes in different biological pathways such as neurodevelopmental, hormone-related, cartilage and bone development pathways, based on their potential functional roles in the respective pathway, to understand the pathology of the disorder.

Automatic axial vertebral rotation estimation on radiographs for adolescent idiopathic scoliosis by deep learning

PurposeAdolescent idiopathic scoliosis (AIS) is a three-dimensional spine deformity governed by lateral curvature and axial vertebral rotation (AVR). Estimating AVR is important for treatment decisions and the prediction of AIS progression. However, manual AVR measurements have intra-observer and inter-observer errors, and therefore this paper proposes an automatic AVR measurement method to address the low precision issue of manual measurement. MethodWe develop an improved feature extraction module for vertebral landmark detection and pedicle segmentation. The improved coordinate convolution layer combined Polarized Self-Attention mechanism is applied in the feature extraction module to help the High-resolution Network to extract coordinate information. Based on vertebral landmark detection and pedicle segmentation, we propose an automatic AVR measurement algorithm to estimate the AVR. ResultsThe mean radial error (MRE) of vertebral landmark detection is 2.70 mm pixels, and the dice coefficient of pedicle segmentation is 72.45%. Compared with the original model, the MRE decreases by 2.13 mm, and the dice coefficient improves by 4.61%. For the AVR measurement results, the testing set contains 37 spine radiographs, including 481 vertebrae and 962 AVR measurements (481 vertebrae by two observers). The average measurement error is lower than 5°, which is within the standard of clinical measurement error. ConclusionThe results demonstrate that the proposed network performs well in vertebral landmark detection and pedicle segmentation, and the proposed AVR measurement is adopted for clinic diagnosis of AIS. SignificanceOur method achieves automatic AVR measurement, reducing the error introduced by manual measurement and improving the efficiency of orthopedists.

Development of Notch-Free, Pre-Bent Rod Applicable for Posterior Corrective Surgery of Thoracolumbar/Lumbar Adolescent Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS), the most common pediatric musculoskeletal disorder, causes a three-dimensional spine deformity. Lenke type 5 AIS is defined as a structural thoracolumbar/lumbar curve with nonstructural thoracic curves. Although a rod curvature will affect clinical outcomes, intraoperative contouring of the straight rod depends on the surgeon's knowledge and experience. This study aimed to determine the optimum rod geometries to provide a pre-bent rod system for posterior spinal surgery in patients with Lenke type 5 AIS. These pre-bent rods will be beneficial for achieving proper postoperative outcomes without rod contouring based on surgeon experience. We investigated 20 rod geometries traced in posterior spinal reconstruction in patients with Lenke type 5 AIS. The differences between the center point clouds in each cluster were evaluated using the iterative closest point (ICP) method with modification. Before the evaluation using the ICP method, the point clouds were divided into four clusters based on the rod length using a hierarchical cluster analysis. Because the differences in the values derived from the ICP method were <5 mm for each length-based cluster, four representative rod shapes were generated from the length-based clusters. We identified four optimized rod shapes that will reduce operation time, leading to a decreased patient and surgeon burden.

Automatic 3-D spine curve measurement in freehand ultrasound via structure-aware reinforcement learning spinous process localization

Freehand 3-D ultrasound systems have been advanced in scoliosis assessment to avoid radiation hazards, especially for teenagers. This novel 3-D imaging method also makes it possible to evaluate the spine curvature automatically from the corresponding 3-D projection images. However, most approaches neglect the three-dimensional spine deformity by only using the rendering images, thus limiting their usage in clinical applications. In this study, we proposed a structure-aware localization model to directly identify the spinous processes for automatic 3-D spine curve measurement using the images acquired with freehand 3-D ultrasound imaging. The pivot is to leverage a novel reinforcement learning (RL) framework to localize the landmarks, which adopts a multi-scale agent to boost structure representation with positional information. We also introduced a structure similarity prediction mechanism to perceive the targets with apparent spinous process structures. Finally, a two-fold filtering strategy was proposed to screen the detected spinous processes landmarks iteratively, followed by a three-dimensional spine curve fitting for the spine curvature assessments. We evaluated the proposed model on 3-D ultrasound images among subjects with different scoliotic angles. The results showed that the mean localization accuracy of the proposed landmark localization algorithm was 5.95 pixels. Also, the curvature angles on the coronal plane obtained by the new method had a high linear correlation with those by manual measurement (R = 0.86, p < 0.001). These results demonstrated the potential of our proposed method for facilitating the 3-D assessment of scoliosis, especially for 3-D spine deformity assessment.

BIOMECHANICAL STUDY OF LATERAL LUMBAR INTERBODY FUSION VERSUS A POSTERIOR FIXATION WITH PEDICLE SCREWS AND RODS USING A HUMAN CADAVERIC MODEL

Lateral lumbar interbody fusion (LLIF) has biomechanical advantages due to the preservation of ligamentous structures (ALL/PLL), and optimal cage height afforded by the strength of the apophyseal ring. We compare the biomechanical motion stability of multiple levels LLIF (4 segments) utilising PEEK interbody 26mm cages to stand-alone cage placement and with supplemental posterior fixation with pedicle screw and rods.Six lumbar human cadaver specimens were stripped of the paraspinal musculature while preserving the discs, facet joints, and osteoligamentous structures and potted. Specimens were tested under 5 conditions: intact, posterior bilateral fixation (L1-L5) only, LLIF-only, LLIF with unilateral fixation and LLIF with bilateral fixation. Non-destructive testing was performed on a universal testing machine (MTS Systems Corp) to produce flexion-extension, lateral-bending, and axial rotation using customized jigs and a pulley system to define a non-constraining load follower. Three-dimensional spine motion was recorded using a motion device (Optotrak).Results are reported for the L3-L4 motion segment within the construct to allow comparison with previously published works of shorter constructs (1-2 segments). In all conditions, there was an observed decrease in ROM from intact in flexion/extension (31%-89% decrease), lateral bending (19%-78%), and axial rotation (37%-60%). At flexion/extension, the decreases were statistically significant (p&lt;0.007) except for stand-alone LLIF. LLIF+unilateral had similar decreases in all planes as the LLIF+bilateral condition. The observed ROM within the 4-level construct was similar to previously reported results in 1-2 levels for stand-alone LLIF and LLIF+bilateral.Surgeons may be concerned about the biomechanical stability of an approach utilizing stand-alone multilevel LLIF. Our results show that 4-level multilevel LLIF utilizing 26 mm cages demonstrated ROM comparable to short-segment LLIF. Stand-alone LLIF showed a decrease in ROM from the intact condition. The addition of posterior supplemental fixation resulted in an additional decrease in ROM. The results suggest that unilateral posterior fixation may be sufficient.

Towards improving the accuracy of musculoskeletal simulation of dynamic three-dimensional spine rotations with optimizing model and algorithm.

The accuracy of musculoskeletal simulations greatly relies on model structures and optimization algorithms. This study investigated the unclarified influence of accounting for several commonly-simplified different model components and optimization criteria on spinal musculoskeletal simulations. The study constructed a full-body musculoskeletal model with passive components of functional spinal units and spinal muscles subject-specifically refined. A muscle redundancy solver was built with 15 optimization criteria. Three-dimensional spine rotations and spinal muscle activities were measured using optical motion capture and electromyogram techniques when eight healthy volunteers performed standing, flexion/extension, lateral bending, and axial rotation. The effect of the model with four different conditions of the passive components and the sensitivity of the 15 optimization criteria on simulations were investigated. Accounting for the refined passive components significantly improved the simulation accuracy. Different optimization criteria behaved distinctly for different motions. Generally minimizing the sum of squared muscle activations outperformed the others, with the highest averaged correlation coefficient (0.82) between the estimated erector spinae muscle activations and measured electromyography and with the estimated joint compression forces comparable to in vivo reference data. This study highlights the importance of passive model components and proposes a suitable optimization framework for realistic spinal musculoskeletal simulations.

A novel Hinge-Link correction system for vertebral column resection: a pilot study in a porcine model.

To introduce a novel Hinge-Link (HL) correction system for vertebral column resection (VCR) in the most severe scoliosis and surgically assess the device in a porcine scoliosis model. The HL was introduced and described how it works on a reproduced three-dimensional spine model of severe scoliosis. A right thoracic scoliosis was surgically created in five 4-month-old pigs. Two weeks later, the VCR was performed to correct the deformity using the HL to test its feasibility and neurological safety in the pig scoliosis model. The surgically created right thoracic scoliosis averaged 32° ± 9.3 prior to the VCR. All animals tolerated the VCR procedure awakening neurologically intact and ambulated for 24h. The HL takes advantage of the ability to provide three-dimensional correction of the deformity and excellent control of the spine segments to prevent damage to the spinal cord in the VCR procedure. The mean correction of the scoliosis was 94% correcting to 1.8° ± 0.8. At sacrifice, the pathological anatomy of the neural axis demonstrated no vertebral subluxation and no dural impingement in any animal. The HL was feasible and neurologically safe for the VCR procedure in the pig scoliosis model. It can provide significant correction of the spinal deformity with appropriate mild shortening at the resected levels and overall lengthening without neurologic deficits. The rigid control of the spine segments provided by this device should allow for improved correction with decreased neurologic deficits and potentially shorter surgical time.

An Advanced Comprehensive Physiotherapy Management for Empyema Thoracis and Scoliosis: A Case Report

Tuberculous empyema is caused by Mycobacterium tuberculosis infection of the pleural cavity, resulting in purulent pleural fluid formation. Tuberculous empyema most commonly develops in patients with tuberculous pleuritis treated with artificial pneumothorax. However, it can also develop in patients with chronic tuberculous pleuritis, usually in patients with pulmonary tuberculosis treated with antituberculous chemotherapy. Scoliosis is a three-dimensional spine deformity caused by several factors, including genetic susceptibility, anterior and posterior spinal development imbalance, and connective tissue abnormalities (skeletal muscle and nerves). Although surgery is the most talked-about treatment option, there is high-quality evidence suggesting the use of conservative therapy in the management of scoliosis. A systematic rehabilitation plan with a variety of approaches was developed, and it was found to be a highly successful protocol for treating the patient's empyema and scoliosis.

Digitization of three-dimensional spine curvature profile in adolescent idiopathic scoliosis using anatomical palpation

ABSTRACT The need for spaced radiological follow-up of adolescents with idiopathic scoliosis (AIS) stimulates the development of radiation-free methodologies to document spinal curvature parameters. The aim of the study was to develop a methodology, referred to as A-Palp, using index finger pulp palpation to assess 3D spinal curvature in the standing position in patients and control group. To estimate repeatability for 2D/3D curvature angles, three manual palpations of spinal curvature were performed by one examiner using an index finger pulp calibrated in an optoelectronic system to acquire these curvature angles in the sagittal and frontal planes and in the 3D plane of maximum curvature. The intrarater repeatability was analysed by generalisability theory and the dependability index ϕ combined with a decision D-study to judge the number of desirable repetitions. The A-Palp/radiograph concurrent validity of 2D/3D apex angles was studied by linear regression and Bland–Altman plot. For the scoliosis angle in AIS patients, the ϕ index was excellent, above 0.9, with a standard error of measurement and minimal detectable change below 3° and 9°, respectively. For A-Palp/radiograph comparison, 95% of 2D and 3D measurement results were between 8° and 11° below and 12° and 5° above the radiographic apex angle, respectively, with a bias below 3°. The good repeatability and concurrent validity show that this innovative radiation-free 3D methodology seems suitable for the assessment of AIS patients when the same examiner repeats the measurement two or three times according to the D-study.

The Effect of PEEK-Rod Fixation Systems on Finite Element Lumbar Spine Model

Orthopedic fixation devices have been employed in the treatment of spinal diseases. Special fixation devices have been developed to decrease the effect of spinal injuries and deformities and have been used to decrease the neurologic back pain of the patients. In this study, the finite element spine model of an adolescent idiopathic scoliotic patient was constructed. The titanium spinal implant system and the system of polyetheretherketone (PEEK) were compared regarding their stress distributions. The finite element lumbar spine model from L2 to L5 vertebra was obtained from computed tomography scan data. The three-dimensional spine model consisted of four lumbar vertebrae, three intervertebral discs, six facet joints, and the corresponding ligaments. Loading and boundary conditions were applied to the L2-L5 lumbar model. According to the subjected loads and bending moments on the model, stress distributions were evaluated especially on the intervertebral discs, and the screw-rod implant systems both for the titanium and the PEEK-based fixation systems. The disc structures were also analyzed for the effects of adjacent segment disease, which has been reported as a post-operative effect of fusion surgeries. Ansys software was used for the simulation processes of the models without the implant system and the models with different fixation systems. Comparative investigation between different fixation systems showed that the stress distribution values were decreased with the PEEK-based fixation system. Moreover, lower total deformation and equivalent stress values were recorded with the PEEK-based fixation system, especially on L3-L4 and L4-L5 intervertebral discs. Furthermore, both spinal implant systems allowed to decrease the overall loading stress on the whole spine models. And it was concluded that the PEEK-based spinal implant system was considerably reduced the load on the discs and ligaments, and also appeared as a better option in stress reduction and load sharing when compared to the titanium spinal implant system.

Patient handling through moving of the beds and stretchers

Transorting patients in beds and stretchers throughout hospitals is a significant manual handling concern for transport teams, nurses, and nursing aides. The objective of this study was to evaluate a power-drive intervention when pushing beds and stretchers with different weight patients. Twelve participants were part of a laboratory simulation where beds and stretchers were pushed down a straight away, around a corner, down a ramp, and up a ramp with and without utilization of the power-drive feature. Peak three-dimensional spine loads were estimated during the trials. In all, power-drive reduced the three-dimensional spine loads by 8%–21% as compared to the manual pushing of the beds and stretchers. Larger reductions were found for the tasks performed with the bed as opposed to the stretcher. The inexperience of the participants may have reduced the benefit of the power-drive as they appeared to not use it to the full extent. To minimize the loads being placed on healthcare providers’ spines and reduce the potential for injury hospitals should implement power-drive technologies on beds and stretchers.

Spinal Biomechanical Modelling in the Process of Lumbar Intervertebral Disc Herniation in Middle-Aged and Elderly.

Lumbar disc herniation is one of the common clinical diseases of the lower lumbar spine in orthopedics. The purpose is to remove the herniated disc nucleus pulposus tissue, remove the compressed part of the disease, and relieve symptoms, such as nerve pain. In the past, biomechanics research mostly relied on in vitro measurements, but the complicated internal environment of the human body prevented us from further measurement and research. However, with the development of computer technology, the use of computer CT scanning, software three-dimensional reconstruction, and displacement study three-dimensional spine biomechanics method makes the research of biomechanics into in vitro simulation stage and has gradually become the focus of current research. The postoperative biomechanics was simulated and the comparison model was established at the same time. At the same time, we combined the clinical follow-up data and studied the clinical data for the treatment of postoperative recurrence of lumbar disc herniation. We compared and analyzed the initial operation method and the experimental results and obtained the prevention of recurrence. The results showed that when one inferior articular process was removed, the lumbar spine appeared unstable to rotate to the opposite side; when one inferior articular process was completely removed, the movement of the lumbar spine in all directions was unstable. Better research on the biomechanical properties of the spine will help the diagnosis and treatment of clinical lumbar disc herniation. Therefore, when performing posterior lumbar spine surgery, not only should the exposure of the surgical field and thorough decompression be considered, but also the biomechanical properties of the lumbar spine should be comprehensively evaluated.

Spinal segment ranges of motion, movement coordination, and three-dimensional kinematics during occupational activities in normal-weight and obese individuals

Measurements of spinal segment ranges of motion (RoMs), movement coordination, and three-dimensional kinematics during occupational activities have implications in occupational/clinical biomechanics. Due to the large amount of adipose tissues, obese individuals may have different RoMs, lumbopelvic coordination, and kinematics than normal-weight ones. We aimed to measure/compare trunk, lumbar, and pelvis primary RoMs in all anatomical planes/directions, lumbopelvic ratios (lumbar to pelvis rotations at different trunk angles) in all anatomical planes/directions and three-dimensional spine kinematics during twelve symmetric/asymmetric statics load-handling activities in healthy normal-weight and obese individuals. Kinematics/motion data were collected from nine healthy young male normal-weight and nine age/height/sex matched obese individuals via a ten-camera Vicon motion capture system. Obese individuals had significantly smaller (p < 0.05) lumbar flexion (~9° in average) and larger pelvis right lateral bending (~5°) RoMs as well as smaller lumbopelvic ratios (~37%) in lateral bending and axial rotation movements as compared to normal-weight individuals. Moreover, the two groups had generally non-significant different segmental orientations (<20° and in most cases < 10°) in load-handling tasks that depended on the magnitude of load asymmetry angle (p < 0.05). Differences were larger for tasks performed near the floor, away from body, and at larger load asymmetry angles. Biomechanical models simulating pure lateral bending, axial rotation, or tasks involving large load asymmetry may therefore need subject-specific, rather than population-based, motion analysis due to the effects from body weight. In clinical applications, it should be noted that healthy obese individuals may have different RoMs and lumbopelvic rhythms than healthy normal-weight individuals in some anatomical planes/directions.

Three-dimensional spine morphology measuring technology for daily surface monitoring

In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests' results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.

Cervicothoracic Manipulation Techniques Reviewed Utilizing Three-Dimensional Spine Model.

Currently, there is a paucity of studies that describe prone cervicothoracic joint high-velocity low-amplitude (HVLA) thrust techniques using an anatomically accurate, biomimetic three-dimensional (3D) spine model for educational demonstration. The purpose of this technical report was to present a learning model for two prone cervicothoracic HVLA thrust techniques using a 3D model, review intersegmental mobility observed on a 3D spine model with application of the techniques, and lastly discuss potential applications of this learning model.