Vertebral Column Research Articles

Vertebral morphology and intracolumnar variation of the iconic African viperid snake Atheris (Serpentes, Viperidae).

We here provide a detailed description of the vertebral morphology of the African arboreal viperid snakes of the genus Atheris. Vertebrae of three different species of the genus, i.e., Atheris desaixi, Atheris hispida, and Atheris katangensis, were investigated via the aid of μCT (micro-computed tomography) scanning. We describe several vertebrae from different regions of the vertebral column for all three species, starting from the atlas-axis complex to the caudal tip, in order to demonstrate important differences regarding the intracolumnar variation. Comparison of these three species shows an overall similar general morphology of the trunk vertebrae among the Atheris species. We extensively compare Atheris with other known viperids. As the sole arboreal genus of Viperinae the prehensile nature of the tail of Atheris is reflected in its caudal vertebral morphology, which is characterized by a high number of caudal vertebrae but also robust and anteroventrally oriented pleurapophyses as a skeletal adaptation, linked with the myology of the tail, to an arboreal lifestyle. We anticipate that the extensive figuring of these viperid specimens will also aid identifications in paleontology.

Dynamic Modelling of the Spine for the Estimation of Vertebral Joint Torques using Gordon’s Method

World Health Organization (WHO) recognised musculoskeletal disorder (MSD) as the main contributor to disability worldwide, with low back pain as the major disorder globally. The occupational disorder normally occurs during lifting. The weight of the load and manual handling tasks during lifting has an impact on the spine and joint torque. The purpose of this study is to propose a dynamic model of the spine that can estimate the vertebral joint torques. This study is a bimodal approach that consists of the experimental and theoretical parts. Ten healthy UniMAP students (10 males) participated in this study. The subjects were required to lift a 3kg weight plate for kinematics and EMG data collection. Retro-reflective markers were attached to the subject body, and then, the data was collected and stored in QTM software. Kinematic data was processed using C-Motion Visual3D. Eight Trigno Wireless Sensors were attached on the back muscles (left and right erector spinae, latissimus dorsi, external oblique and internal oblique). The EMG data were stored in EMG Acquisition software and subsequently, were processed using EMG Analysis software. Gordon’s method was used to develop a mathematical model of the spine. The model comprises of five kinematic chains which connected three lumbar, two thoracic and one cervical. The model calculated the value of joint torque on flexion/extension movement using Matlab and Microsoft Excel. When calculated on L5, the model gives an estimation within 0 – 30 kgm2s-2. The model was further used to estimate value of L3, L1, MAI and T2. The estimate average value of joint torque at L3 is within 5 – 25 kgm2s-2, MAI is within 0 – 6 kgm2s-2 and T2 is within 0 – 1 kgm2s-2. The average RMS values show the highest muscle activity on the right internal oblique muscle (1519 µV), followed by the right external oblique (1166 µV) and left external oblique (418 µV). The results obtained gives an insight on the value of joint torque that have been applied by the spine and the most activated back muscles during lifting.

Intervertebral osteointegration and biomechanical performance of bioactive lithium disilicate glass-ceramic scaffold fabricated by digital light processing

The high strength of lithium disilicate (LD) glass-ceramic makes it difficult to form complex orthopaedic scaffolds using traditional methods. In addition, the osteointegration behavior of LD has also not been well studied in vivo. This study aimed to investigate the procedure of digital light processing (DLP) for fabricating porous LD glass-ceramic scaffolds and to assess the intervertebral osteointegration and biomechanical performance of the scaffolds. The phase formation, fracture morphology, flexural strength and density of LD glass-ceramics fabricated by DLP were evaluated to optimize the manufacturing process. Cell proliferation, cell differentiation and mineralization on the optimized glass-ceramics were recorded for comparison with traditional cast glass-ceramics (CG). The porous LD glass-ceramics scaffold was implanted into rabbits for 7 w and 14 w and then assessed using micro-CT and histological staining. Compression testing was also used to understand the scaffold’s mechanical properties. Furthermore, the scaffold was inserted into a validated finite element model of a human lumbar spine to study the stress distribution during physiological motions. The results indicated that LD glass-ceramics with step-by-step crystallization formed principal phases of Li2Si2O5 and Li3PO4, which had the highest flexural strength. Cell proliferation, cell differentiation and mineralization on the glass-ceramics formed by DLP were similar to the results of glass-ceramics formed by casting. The porous LD glass-ceramic scaffold promoted osseointegration in rabbits and was capable of withstanding physiological loads that would be experienced in a human lumbar spine. In conclusion, the bioactive LD glass-ceramic developed in this study showed good osteogenesis with sufficient mechanical performance, potentially making it suitable for applications in intervertebral fusion.

Morphometric analysis of the spinal cord in patients undergoing posterior vertebral column subtraction osteotomy for recurrent tethered cord syndrome.

In posterior vertebral column subtraction osteotomy (PVCSO), a section of a thoracic or lumbar vertebra and the adjacent disc are resected to shorten the spinal column, aiming to permanently alleviate tension on the spinal cord in patients with recurrent tethered cord syndrome (TCS). The effects of this procedure on the spinal cord are not well characterized. This study investigated morphometric changes in the cord following PVCSO and assessed associated clinical outcomes in patients with recurrent TCS. A retrospective review of patients with recurrent TCS undergoing PVCSO with robotic assistance at the authors' tertiary care institution between 2019 and 2023 was performed. Clinical data were recorded from electronic medical records, and morphometric measurements, including T12-L2 sagittal height, intradural diameter, and the diameters, area, eccentricity, and positioning of the spinal cord, were collected from MRI. Spinal cord dimensions including anteroposterior and lateral diameters, area, eccentricity, positioning, and intradural diameter were compared before and after surgery. Six patients were included in this study. At 6-week follow-up, all patients had improvement on lower-extremity motor function examinations, 40% had improvement on lower-extremity sensory function examinations, and 83% had improved self-reported pain. Bladder and bowel incontinence were improved in 50% and 60%, respectively. PVCSO reduced the height of the spinal column by a mean of 18.1 ± 5.2 mm. PVCSO increased the mean spinal cord anteroposterior diameter by 0.8 ± 0.5 mm at T12 (p = 0.03) and the mean area by 0.4 ± 0.3 mm2 at T12 (p = 0.03). The mean eccentricity of the spinal cord decreased by 0.15 ± 0.15 at L1 (p = 0.05), indicating that the spinal cord became more circular after surgery. No major complications were reported, although 1 patient experienced atelectasis and pulmonary embolism postoperatively. This study provides novel insights into the morphometric changes induced by PVCSO and their correlation with clinical outcomes in patients with TCS. The procedure effectively increased spinal cord dimensions, alleviating tension and offering potential benefits in symptom relief. The study underscores the need for objective metrics to guide surgical decision-making and enhance the long-term success of PVCSO in the management of TCS.

A long gestation: spine anatomy from the medieval age to the end of the 19th century. An analytical historical review.

The discovery of spine anatomy followed a problem/solution pattern; it took almost 1000 years to transition from nihilism to perfectionism. Before the 16th century, the main issue was accessing and opening the spine. The level of knowledge progressed rapidly when the spinal canal was opened longitudinally during the 16th century. The 17th century was an incubation period that allowed the consolidation of the science of anatomy with the help of art, philosophy, and other sciences. In particular, the conservation of the cadaver was improved. Famous spine anatomists were close to Rembrandt, master of the chiaroscuro technique, which helped to improve the anatomical drawings significantly. Descriptions of the pathological anatomy of the spine were first published early in the 17th century, but progress was slow up to the end of the 18th century due to a lack of occasions for clinical-pathological correlations. Normal anatomy became remarkably accurate in the 18th and 19th centuries when soft tissues and connections (e.g., among the intervertebral discs) were studied in detail. The slow compressions due to underlying diseases and then the degenerative processes were subsequently described.

Unintended readmissions and reoperations within 30 and 90 days following adult spinal deformity surgery.

This study investigated the rates and etiologies of unintended readmissions and reoperations within 30 and 90 days after adult spinal deformity (ASD) surgery. The authors aimed to identify the risk factors for readmission and reoperation by analyzing patient demographic and surgical characteristics. This retrospective cohort study included 307 consecutive patients who underwent surgery for ASD from 2012 to 2022 at a single academic institution. Data were collected on patient demographic characteristics, comorbidities, operative details, and postoperative complications. Chi-square and multivariable logistic regression models were used to identify the risk factors associated with 30- and 90-day readmissions and reoperations. The mean ± SD age at surgery was 66.6 ± 10.5 years, and the majority (80.8%) of patients were female. The 30-day and 90-day readmission rates were 11.7% and 15.3%, respectively. Multivariable regression for 30-day readmissions revealed that length of hospital stay (LOS) after index surgery of > 20 days (OR 2.48) and surgical factors such as vertebral column resection (VCR) (OR 4.26) and pelvic fixation (OR 4.38) were risk factors. Other factors such as the American Society of Anesthesiologists Physical Status Classification System (ASA) class, prior spine surgery, and age were not associated with 30-day readmissions. Ninety-day readmission was associated with high ASA class (OR 2.37) and LOS > 20 days (OR 2.82). The 30- and 90-day reoperation rates were 7.8% and 10.1%, respectively. The variables associated with 30-day reoperations were intraoperative VCR (OR 3.34) and LOS > 20 days (OR 9.38). Ninety-day reoperations were associated with dural tears (OR 3.33) and LOS > 20 days (OR 3.68). This study provides valuable insights into the incidence of unintended readmission and reoperation within 30 and 90 days after ASD surgery in an Asian population. By identifying the associated risk factors, healthcare providers can customize surgical strategies and optimize perioperative care to effectively mitigate these events.

A Retrospective Analysis of 190 Patients With Scoliosis Referred to a Private Australian Clinical Advisory Service Between 2017 and 2020

ObjectiveThe aim of this study was to describe the demographic and clinical characteristics of patients with scoliosis from Australian primary care practices. MethodsA retrospective review of 190 patient records from August 2017 to April 2020 from a private Australian clinical advisory service database was performed. Deidentified demographic and clinical data were collated and analyzed, along with information regarding the referring practitioners and any accompanying clinical or paraclinical information. Numerical data were summarized with median and IQR, while categorical data were summarized with counts and percentages. Salient qualitative data from the advisory service records were also collated, coded, and summarized. ResultsPatients were aged between 3 and 87 years; the majority (71%) of patients were female, with a median age of 16 years (IQR, 13; range, 3-87 years). The most common type of spinal deformity seen in the sample was scoliosis (92%), with hyperkyphosis (7%) and other deformity (1%) making up the remaining cases. There was a wide variety of scoliosis presentations; however, curves were commonly (45%) located in the thoracic region of the spine. Observed scoliosis cases were of moderate severity with a median Cobb angle measuring 26.5° (IQR, 20°). Reports of pain were in the lower trunk/pelvis (46%), the middle trunk (16%), or throughout multiple bodily regions (27%). Alterations in normal spinal anatomy (eg, hemivertebrae) were common (55% of cases). The majority (86%) of patient cases came from chiropractors, whereas 9% were from osteopaths, 4% from physiotherapists, and 1% from other types of practitioners (eg, medical practitioners). ConclusionThe findings from this study suggest that patients presenting to practitioners in primary care settings in Australia present with a range of scoliosis and related spinal deformity presentations.

Retrospective analysis of fractures in crab-eating foxes (Cerdocyon thous)

This study assessed axial and appendicular fractures in crab-eating foxes (Cerdocyon thous; Linnaeus, 1766) admitted to the Reference Center for Wildlife. Medical records and plain radiographs of C. thous were retrospectively evaluated. Seventy-four free-ranging C. thous were admitted over 10 years, of which 21 had fractures in the appendicular and/or axial skeleton. Appendicular skeleton fracture was verified in 42.86 % of the animals, five of whom had long bone involvement and four the hip bones. More than one fracture in the appendicular skeleton occurred in 14.28 % of the animals, with the most common being a long bone fracture with a hip fracture. Axial skeleton fractures were observed in 9.52 % of the cases, with one fracture located in the vertebral column and the other in the head. Five animals died and nine were euthanized due to injury severity, prognosis and/or poor outcome after treatment. Seven animals showed good evolution after treatment, and four animals were released. In conclusion, hip bone fractures, isolated or combined with injuries to other bones of the axial and/or appendicular skeleton, were the most common injuries in C. thous. The characteristics of multiple trauma were associated with high mortality and complications.

Cervical ossification of the posterior longitudinal ligament revealed by cervical trauma: A case report with literature review

Background: Ossification of the posterior longitudinal ligament (OPLL) refers to bone formation within the posterior longitudinal ligament of the spinal column. This disease of the cervical spine results in a reduced volume of the spinal canal and can cause spinal cord damage. The onset of cervical OPLL is insidious. OPLL may increase the risk of spinal cord injury with various neurological deficits after minor trauma. An acute event can reveal a previously unknown or paucysymptomatic cervical OLLP. The aim: To present a case of unknown cervical OLLP revealed by cervical trauma after a traffic road accident. Case report: A 47-year-old female presented intractable cervicobrachial neuralgia in the posttraumatic aftermath of a traffic road accident. Computed Tomography (CT) and Magnetic resonance imaging (MRI) demonstrated an isolated OPLL from C5 to C6, causing significant nerve compression operated via anterior approach with discectomy and intervertebral cervical cage. Conclusion: Acute cervical trauma must be considered a mode of revelation of previously unknown or paucisymptomatic cervical OLLP and must be considered in the emergency room.

Septic paravertebral abscess and inferior vena cava thrombosis complicated by uro-sepsis: Case report

Paravertebral abscess is an uncommon and potentially dangerous illness characterized by the buildup of pus in the anatomical area surrounding the spinal column. A 65-year-old female, who has diabetes and high blood pressure, came in with intense discomfort in her lower back that spreads to her lower limbs, making it difficult for her to move. She also has a high fever, excessive sweating, and has lost a large amount of weight. The blood tests indicate the following abnormalities: low Hb level of 9.6 g/dl, low MCV of 70 fl, elevated total white blood cell count of 15.8 × 109/L, elevated neutrophil count of 12.4 × 109/L, normal lymphocyte count of 2.8 × 109/L, high platelet count of 485 × 109/L, and elevated ESR of 110 mm/hr. The level of phosphatase was raised to 247 U/L, which is beyond the usual range of 40-150 U/L. The blood film reveals the presence of hypochromic microcytic red blood cells, which are indicative of iron deficiency anemia. There is also evidence of neutrophil leukocytosis in the white blood cells, with no immature cells observed. Additionally, an increase in platelets is observed in the film. The D-dimer level is 2009 ng/ml, which is within the normal range of less than 500 ng/ml. The CRP level is 48 gm/l, which is above the usual range of less than 6 gm/l. The bone marrow testing yielded normal results. The blood culture indicated the presence of Streptococcus epidermidis growth. Radiological tests revealed that a CE-MRI of the dorsal and lumbar spine indicated the presence of a para-aortic abscess together with septic thrombosis of the inferior vena cava. Paravertebral abscess is a critical emergent condition required a necessary therapy protocols to stabilize the patient status. The timing of intervention is crucial in cases of paravertebral abscess, as the existence of a mass can led to spinal cord compression.

Impact of transpedicular fixation on thoracolumbar junction burst fracture stability: a biomechanical perspective

Introduction. The treatment of burst fractures at the thoracolumbar junction remains a contentious issue in vertebrology. Despite a broad array of surgical interventions available, many surgeons favor isolated posterior stabilization, which can be performed using either minimally invasive or open approaches. However, the biomechanical properties of these methods have not been thoroughly investigated. Objective: This study aims to evaluate the biomechanical stability of the thoracolumbar junction following transpedicular stabilization of a burst fracture at the Th12 vertebra, under different system configurations influenced by lateral flexion. Materials and Methods: A mathematical finite element model of the human thoracolumbar spine, featuring a burst fracture at the Th12 vertebra, was developed. The model included a transpedicular stabilization system with eight screws, simulating “long” stabilization. We examined four variants of transpedicular fixation using both mono- and bicortical screws, with and without the inclusion of two cross-links. Results: The study found that the load borne by the damaged Th12 vertebral body varied depending on the fixation system employed. Specifically, stress levels were 24.0 MPa, 27.3 MPa, 18.4 MPa, and 25.8 MPa for models with short screws without cross-links, long screws without cross-links, short screws with cross-links, and long screws with cross-links, respectively. At the screw entry points in the vertebral arch, the highest stress values were recorded at the L2 vertebra, showing 11.8 MPa, 14.0 MPa, 9.4 MPa, and 13.4 MPa for each respective model. Among the metal construct elements, the connecting rods consistently exhibited the highest stress, with values of 226.7 MPa, 313.4 MPa, 212.4 MPa, and 293.98 MPa, respectively. Conclusion: The results underscore that utilizing cross-links in the stabilization of burst fractures at the thoracolumbar junction, which is only feasible through an open installation, somewhat mitigates stress within the stabilized spinal segment. Meanwhile, the modeling of lateral flexion revealed only minimal differences in stress values between open and minimally invasive installations.

Establishing a Primary Dorsal Root Ganglia Cell Culture from a Rat Spinal Column

Establishing a Primary Dorsal Root Ganglia Cell Culture from a Rat Spinal Column

Establishing a Primary Dorsal Root Ganglia Cell Culture from a Rat Spinal Column

Establishing a Primary Dorsal Root Ganglia Cell Culture from a Rat Spinal Column

Are the Umbilicus and Iliac Crests Truly at the Level of L4 to L5? A Computed Tomography-Based Study of Surface Anatomy of the Anterior Lumbar Spine.

This study aimed to determine whether the iliac crests are truly at the level of L4 to L5, accounting for patient demographic and anthropometric characteristics. We measured the umbilicus and iliac crests relative to the lumbar spine using computed tomography of patients without spinal pathology, accounting for the influences of patient height, weight, body mass index (BMI), sex, race, and ethnicity. A total of 834 patients (391 men and 443 women) were reviewed. The location of the umbilicus relative to the lumbar spine demonstrated a unimodal distribution pattern clustered at L4, while the iliac crests were most frequently located from L4 to L5. Iliac crests were located above the L4 to L5 disc space 26.5% of the time. Iliac crests were located at the L4 to L5 disc space 29.8% of the time. No correlations were observed between the umbilicus and iliac crests with patient height, weight, or BMI. There was no difference in the location of the umbilicus with respect to patient sex, race, and ethnicity. The locations of the iliac crests were cephalad in women compared with men and in Hispanics compared with African American, Caucasian, and Asian patients. The iliac crests were located above the level of the L4 to L5 disc space approximately 26% of the time. The umbilicus is most frequently at the level of the L4 vertebral body. Patient height, weight, and BMI do not influence the location of the umbilicus or the iliac crests relative to the lumbar spine. Patient sex and ethnicity influence the location of the iliac crests but not the umbilicus relative to the lumbar spine. Modern neurosurgical techniques require clearance of the iliac crests during anterior and anterolateral approaches. Understanding the level of the iliac crests is crucial in planning for transpsoas fusion approaches.

The first lacertid and partly articulated snake from the Middle Miocene of the Devínska Kobyla Hill in Slovakia, from the type locality of the earliest known seal

I here describe lacertid and snake remains from the classic Middle Miocene (MN 6) locality Bonanza of the Devínska Kobyla Hill near Bratislava (Slovakia). The locality is famous for being a type locality of an early seal Devinophoca Koretsky & Holec, 2002. During the Middle Miocene, the area of Devínska Nová Ves was part of an archipelago in the western part of the Central Paratethys in the northern part of the Vienna basin. The fossils described here comprise an incomplete left maxilla of a lacertid lizard and an articulated portion of a vertebral column of a small colubrid snake with several ribs still attached. The maxilla is tentativelly allocated here to Lacerta Linnaeus, 1758 and is a rare instance of the occurrence of the clade Lacertidae Oppel, 1811 in this environment during the Middle Miocene. Moreover, it represents the oldest known occurence of this clade in Slovakia. Articulated snake specimens from the Cenozoic are rare and although only party articulated, the specimen from Bonanza is therefore exceptional. On the basis of vertebrae alone, determination of fossil colubrids is very difficult. The morphology of the Bonanza specimen is most similar to the extant Dolichophis Gistel, 1868, as also to other small fossil snakes assigned to ‘Coluber’ Linnaeus, 1758 when that genus was a catch-all grade taxon recognised from both Europe and North America, notably ‘Coluber’ dolnicensis Szyndlar, 1987 and ‘Coluber’ pouchetii (Rochebrune, 1880). Because the potentially closest living relative of the European Miocene ‘Coluber’ is Dolichophis, I assigned tentatively the material from Bonanza to cf. Dolichophis, rather than to the wastebasket taxon ‘Coluber’.

Ozone therapy vs. classical treatment in musculoskeletal disorders

With aging and weight gain, the population is significantly overweight and faces additional pressure on vertebral and peripheral joints (ankles, knees, hips, shoulders), which affects muscles, tendons, ligaments, and nerves. Muscle contraction, translated by pain, sends the patient to the doctor. Lumbar and cervical spine disorders occur in 70-80% of the world's population during their lifetime. They are a major problem because they reduce the quality of life and increase the costs borne by health services and patients. There are multiple therapeutic options, both classic medication and alternative treatment, to combat pain for a longer or shorter period. Relief or suppression of pain, the dominant symptom in the manifestations of degenerative arthritic diseases, is an important goal of treatment, ultimately improving the quality of life. Patients, for various reasons, frequently seek alternative therapies, especially to surgical treatment. Finding the most comprehensive treatment is often a challenge. If we consider the benefit that a treatment (therapy) should bring to the health condition, then an individualized therapeutic plan must be chosen. A retrospective study on the effects of ozone and platelet-rich plasma (PRP) treatment compared to classic medication shows the role of ozone therapy in pain relief and the beneficial effect of this therapy, especially in combination with PRP, over a longer period.

Magnetic resonance imaging evaluation of the cerebellar tonsil position before and after posterior spinal fusion in adolescent idiopathic scoliosis.

Chiari malformation type I(CM-I) is one of the most common neurological malformations observed in patients with adolescent idiopathic scoliosis (AIS). It remains uncertain whether AIS patients without neurological symptoms require CM-I decompression before undergoing spinal corrective surgery to prevent cerebellar tonsil herniation and potential neurological complications. This study aims to assess variations in the position of the cerebellar tonsil after posterior spinal fusion (PSF) in neurologically intact patients with AIS. We retrospectively evaluated 40 patients with AIS who underwent posterior spinal fusion (PSF) without neurological symptoms. Sagittal hindbrain MRIs were performed before and after spinal surgery. The cerebellar tonsil's position relative to the foramen magnum was measured using the method described by Aboulezz (J Comput Assist Tomogr 1985). We assessed variations in the cerebellar tonsil position concerning spinal correction and elongation after PSF. The average preoperative magnitude of the scoliotic curve was 53.15 degrees (SD 10.46 degrees), and that of thoracic kyphosis was 35.42 degrees (SD 12.38 degrees). In the immediate postoperative period, the average magnitudes were 7.45 degrees (SD 7.33 degrees) and 27.87 degrees (SD 9.03 degrees), respectively. The average correction achieved with PSF was 86% in the coronal plane (p < 0.00001). The average length of the spine in the coronal plane was 44.5cm (SD 5.25cm) preoperatively and 48.27cm (SD 4.40cm) postoperatively (p < 0.00001). The average length of the vertebral column in the sagittal plane was 50.87cm (SD 4.47cm) preoperatively and 55.13cm (SD 3.27cm) postoperatively (p < 0.00001). No significant difference was observed in the position of the cerebellar tonsil in the measurements taken before and after spinal deformity correction (p = 0.6042). In 10 out of 40 patients, caudal displacement of the cerebellar tonsil was observed after PSF. In 28 patients, no variation in the position of the cerebellar tonsil was observed, and in 2, cephalic displacement was noted. In AIS patients with a normal position of the cerebellar tonsil undergoing posterior spinal fusion, there is no significant change in their positionafter surgery. Our analysis did not reveal any correlation between curve correction, spine elongation, and variations in the cerebellar tonsil position. The position of the cerebellar tonsil remained largely unchanged after PSF in AIS patients without neurological symptoms. Further studies would be necessary to determine whether surgical decompression is required in asymptomatic patients with CM-I before undergoing surgery to correct spinal deformity.

The role of diurnal variation in development of musculoskeletal pain during prolonged standing

BackgroundResearch suggests mechanical changes occur to the body over the course of the day including shrinking of the intervertebral disc height which can increase rotational stiffness and rigidity of the spinal column. Further, pain sensitivity has been observed to fluctuate throughout the day, suggesting variations in pain sensitivity. Previous work has identified biomechanical and neuromuscular features related to the development of musculoskeletal pain during prolonged standing; however, many protocols have not controlled for time of day. Research questionDoes the time of day (i.e., diurnal variation) have an effect on the common neuromuscular and biomechanical variables characterizing the development of standing musculoskeletal pain in a two-hour prolonged standing protocol? MethodsA convenience sample of 20 healthy young adults (10 female and 10 male) completed two 2-hour prolonged standing bouts (8:00 a.m. and 8:00 p.m.) on separate days. Visual analogue scales were used to measure pain perception of the low back, legs, and feet throughout each protocol. Neuromuscular control was measured using surface EMG on muscles of the trunk and lower extremities. Postural sway was captured using measures of joint range of motion, and the analysis of center of pressure trajectory data using a force plate. ResultsDiurnal variation was observed to influence the development of musculoskeletal pain. Specifically, pain perception was found to be increased in the evenings as more participants were classified as pain developers in the PM sessions, and mean leg and foot pain perceptions were higher in the evening. Reduced postural sway patterns, and elevated co-contraction indices were found to be associated with the development of pain. SignificanceThese results suggest that future research assessing standing-pain protocols should control for time of day. Additionally, further research is warranted to explore the mechanistic causes of the development of standing pain.

Development of a chronic compression spinal cord injury model in neonatal and adult rats.

Spinal cord injury presents a significant burden globally, with traumatic spinal cord injury being the predominant cause historically. However, nontraumatic spinal cord injury (NTSCI) is emerging as a significant contributor, particularly in developed nations, yet it remains poorly understood due to underreporting and misclassification. NTSCI, spanning various etiologies such as bony growths, vascular conditions, infections, neoplastic conditions, and immune disorders, poses unique challenges in diagnosis and treatment, often resulting in lifelong morbidity. This study addresses the lack of suitable animal models for NTSCI research, especially in neonatal animals. Utilizing a solid spacer approach, we developed a compression NTSCI model applicable to both neonatal and adult Sprague-Dawley rats. Through anatomical measurements and invivo experiments, we confirmed the feasibility and safety of the spacer insertion procedure and observed no acute off-target effects. The versatility of this model lies in its adaptability to different ages of rats, offering a cost-effective and reproducible means to induce graded injuries. Moreover, behavioral assessments demonstrated observable hindlimb function, validating the model's utility for studying functional outcomes. Although challenges persist, particularly in accounting for spinal column growth in neonatal animals, this model fills a crucial gap in pediatric NTSCI research. By providing a platform to investigate pathophysiological mechanisms and test potential treatments, it offers promising avenues for advancing our understanding and management of pediatric NTSCI.

AXIAL DEFORMATION OF SPINEBIO-TENSEGRITY MODELAT DIFFERENT DEPLOYABLE SCHEMES

The study presents the axial deformation of a spine bio-tensegrity model through a shape change strategy with different deployment schemes. The spine bio-tensegrity model mimics the total height, tapered form and natural curvature of a human spine. Three deployable schemes S1-S3 with a different combination of cables at alterable and fixed lengths (at the lower, middle and upper part of the model, respectively) were investigated to achieve a series of axial displacements at 200 mm, 400 mm and 600 mm in the z-direction. The shape change algorithm was developed to optimise the forced elongation of cables, incorporating an objective function designed for monitored nodes in the system to reach their prescribed targets during the optimisation process. Sequential quadratic programming was employed to solve a nonlinear optimisation problem in the shape change analysis involving inequality constraints. The efficiency of the deployable schemes was evaluated based on the deformed shapes, convergence curve and axial forces of the spine bio-tensegrity model. The finding shows in addition to axial deformation, the model in deployment scheme S1 preserves the slenderness characteristic of the spine. In contrast, the model exhibits excessive expansion in the thoracic region in schemes S2 and S3. Greater total computational steps in deployment scheme S3, followed by S2 and S1, reveal that the active cables set near the monitored nodes allow the model to sense and act faster to reach their targets. The study contributes to understanding the structural behaviour and deployment strategy for a structure mimicking a biological system.