In Vivo Passive Axial Rotational Stiffness of the Thoracolumbar Spine (original) (raw)
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Manual Therapy, 2009
The aim of this study was to evaluate the stability and intra-tester reliability of an innovative approach to measure active thoracic spine axial rotation. Ultrasound imaging of a thoracic vertebra in conjunction with Polhemus motion analysis of the transducer was used to measure axial thoracic spine rotation in a functional position. The range of motion in a convenience sample of asymptomatic subjects (n ¼ 24) was calculated across ten repetitions of a single trial to evaluate stability. The protocol was repeated the same day and 7-10 days later to provide data for within and between day intra-tester reliability. Mean total range of axial rotation was 85.15 degrees across a single trial with SD ¼ 14.8, CV ¼ 17.4, SEM ¼ 3.04. SEM ranged 0.63-3.37 for individual subjects and 2.60-3.64 across repetitions. Stability of performance occurred at repetitions 2-4. Intra-tester reliability (ICC 2,1 ) was excellent within day (0.89-0.98) and good/excellent between days (0.72 0.94). Bland-Altman plots however suggest that agreement may range from 0 to 10% for within day measures and from 0 to 15% for between day measures. Whether this combined approach has sufficient precision and accuracy as a clinical research tool has yet to be fully evaluated.
Reliability of thoracic spine rotation range-of-motion measurements in healthy adults
Journal of athletic training
The reliability of clinical techniques to quantify thoracic spine rotation range of motion (ROM) has not been evaluated. To determine the intratester and intertester reliability of 5 thoracic rotation measurement techniques. Descriptive laboratory study. University research laboratory. Forty-six healthy volunteers (age = 23.6 ± 4.3 years, height = 171.0 ± 9.6 cm, mass = 71.4 ± 16.7 kg). We tested 5 thoracic rotation ROM techniques over 2 days: seated rotation (bar in back and front), half-kneeling rotation (bar in back and front), and lumbar-locked rotation. On day 1, 2 examiners obtained 2 sets of measurements (sessions 1, 2) to determine the within-session intertester reliability and within-day intratester reliability. A single examiner obtained measurements on day 2 (session 3) to determine the intratester reliability between days. Each technique was performed 3 times per side, and averages were used for data analysis. Reliability was determined using intraclass correlation coeff...
Sensors, 2022
Objective: to analyze current active noninvasive measurement systems of the thoracic range of movements of the spine. (2) Methods: A systematic review and meta-analysis were performed that included observational or clinical trial studies published in English or Spanish, whose subjects were healthy human males or females ≥18 years of age with reported measurements of thoracic range of motion measured with an active system in either flexion, extension, lateral bending, or axial rotation. All studies that passed the screening had a low risk of bias and good methodological results, according to the PEDro and MINORS scales. The mean values and 95% confidence interval of the reported measures were calculated for different types of device groups. To calculate the differences between the type of device measures, studies were pooled for different types of device groups using Review Manager software. (3) Results: 48 studies were included in the review; all had scores higher than 7.5 over 10 on the PEDro and MINORs methodological rating scales, collecting a total of 2365 healthy subjects, 1053 males and 1312 females; they were 39.24 ± 20.64 years old and had 24.44 ± 3.81 kg/m2 body mass indexes on average. We summarized and analyzed a total of 11,892 measurements: 1298 of flexoextension, 1394 of flexion, 1021 of extension, 491 of side-to-side lateral flexion, 637 of right lateral flexion, 607 of left lateral flexion, 2170 of side-to-side rotation, 2152 of right rotation and 2122 of left rotation. (4) Conclusions: All collected and analyzed measurements of physiological movements of the dorsal spine had very disparate results from each other, the cause of the reason for such analysis is that the measurement protocols of the different types of measurement tools used in these measurements are different and cause measurement biases. To solve this, it is proposed to establish a standardized measurement protocol for all tools.
Effects of Dorsal Versus Ventral Shear Loads on the Rotational Stability of the Thoracic Spine
Spine, 2007
A biomechanical in vitro study on porcine and human spinal segments. To investigate axial rotational stability of the thoracic spine under dorsal and ventral shear loads. Idiopathic scoliosis is a condition restricted exclusively to humans. An important difference between humans and other vertebrates is the fact that humans ambulate in a fully erect position. It has been demonstrated that certain parts of the human spine, more specifically the dorsally inclined lower thoracic and high lumbar parts, are subject to dorsally directed shear loads. It has been hypothesized that these dorsal shear loads reduce the rotational stability of the spine, thereby increasing the risk to initiate idiopathic scoliosis. Fourteen porcine and 14 human thoracic functional spinal units (FSUs) with intact costotransverse and costovertebral articulations were used for biomechanical testing. In both dorsal and ventral directions, shear loads were applied to the upper vertebra of the FSU in the midsagittal plane (centrally), and at 1 cm to the right and to the left (eccentrically), resulting in a rotary moment. Vertebral rotation was measured at 3 incremental loads by an automated optoelectronic 3-dimensional (3D) movement registration system. The results of this study showed that eccentrically applied shear loads induce vertebral rotation in human as well as in porcine spinal segments. At the mid-thoracic and lower thoracic levels, significantly more vertebral rotation occurred under dorsal shear loads than under ventral shear loads. These data show that, in humans and in quadrupeds, the thoracic spine is less rotationally stable under dorsal shear loads than under ventral shear loads.
Measuring the posteroanterior stiffness of the cervical spine
Manual Therapy, 2008
An essential part of improving manual therapy treatment for cervical spine disorders is the identification of the mechanical effects of manual techniques. The aims of this research were to develop a reliable and safe instrument for measuring cervical spine stiffness, and to document stiffness in a group of asymptomatic individuals.
2011
Our objective was to examine the load-bearing capacity of the transverse processes of human cadaveric thoracic vertebrae to vertical loads and axial rotation moments (i.e., moment applied in the transverse plane). A secondary objective was to examine the effect of the attached rib stumps. We wanted to demonstrate that the transverse process is durable enough to support the CAB hook-a complementary hook to the CD system-and can handle the vertical load or axial rotation moment during correction of scoliosis. We used 107 thoracic vertebrae removed from 10 cadavers. They were prepared in vertebral pairs, and were fixed into a material testing apparatus. Superoinferior vertical loads and axial rotation moments were applied to the transverse process using the CAB hooks at a rate of 30 mm/min and 8.58/s respectively until it fractured. We recorded 142 measurements, 99 were for vertical load and 43 for axial rotation moment. The average ultimate vertical load was 338 (SD ¼ 128) N and the average ultimate axial rotation moment was 14.4 (SD ¼ 4.52) Nm. The ultimate axial rotation moment for specimens with rib stumps attached was significantly greater than for specimens without rib stumps 15.9 (SD ¼ 4.1) Nm versus 12.5 (SD ¼ 4.4) Nm. Our results showed that both the vertical and axial rotation loading capability of the transverse process are large enough to withstand significant correctional forces, without fracture, through the CAB hooks.
A Focused Review – Thoracolumbar Spine: Anatomy, Biomechanics and Clinical Significance
The knowledge of the Thoracolumbar Spine (TS) Anatomy and Biomechanics is important for prevention of mechanical damage of spine; which is very common and presented with the Low Back Pain (LBP). It is still unknown that how the TS commonly gets damaged during daily activities of life. This paper aims to give a comprehensive account of biomechanics of TS and its anatomical and clinical correlation for the occurrence and prevention of mechanical damage of spine.
The biomechanics of the pediatric and adult human thoracic spine
Annals of advances in automotive medicine / Annual Scientific Conference ... Association for the Advancement of Automotive Medicine. Association for the Advancement of Automotive Medicine. Scientific Conference, 2011
A growing body of literature points out the relevance of the thoracic spine dynamics in understanding the thoraxrestraint interaction as well as in determining the kinematics of the head and cervical spine. This study characterizes the dynamic response in bending of eight human spinal specimens (4 pediatric: ages 7 and 15 years, 4 adult: ages 48 and 52 years) from two sections along the thoracic spine (T2-T4 and T7-T9). Each specimen consisted of three vertebral bodies connected by the corresponding intervertebral discs. All ligaments were preserved in the preparation with the exception of the inter-transverse ligament. Specimens were exposed to a series of five dynamic bending ramp-and-hold tests with varying amplitudes at a nominal rate of 2 rad/s. After this battery of tests, failure experiments were conducted. The 7-year-old specimen showed the lowest tolerance to a moment (T2-T4: 12.1 Nm; T7-T9: 11.6 Nm) with no significant reduction of the relative rotation between the vertebrae. The 15-year-old failure tolerance was comparable to that of the adult specimens. Failure of the adult specimens occurred within a wide range at the T2-T4 thoracic section (23.3 Nm-53.0 Nm) while it was circumscribed to the interval 48.3 Nm-52.5 Nm for the T7-T9 section. The series of dynamic ramp-and-hold were used to assess two different scaling methods (mass scaling and SAE scaling). Neither method was able to capture the stiffness, peak moment and relaxation characteristics exhibited by the pediatric specimens.