Relationship between the bilateral ratios of the thoracic shape and electromyographic activity of the thoracic and lumbar iliocostalis muscles during thoracic lateral translation (original) (raw)
Related papers
Anterior thoracic posture increases thoracolumbar disc loading
European Spine Journal, 2005
In the absence of external forces, the largest contributor to intervertebral disc (IVD) loads and stresses is trunk muscular activity. The relationship between trunk posture, spine geometry, extensor muscle activity, and the loads and stresses acting on the IVD is not well understood. The objective of this study was to characterize changes in thoracolumbar disc loads and extensor muscle forces following anterior translation of the thoracic spine in the upright posture. Vertebral body geometries (C2 to S1) and the location of the femoral head and acetabulum centroids were obtained by digitizing lateral, full-spine radiographs of 13 men and five women volunteers without previous history of back pain. Two standing, lateral, fullspine radiographic views were obtained for each subject: a neutralposture lateral radiograph and a radiograph during anterior translation of the thorax relative to the pelvis (while keeping T1 aligned over T12). Extensor muscle loads, and compression and shear stresses acting on the IVDs, were calculated for each posture using a previously validated biomechanical model. Comparing vertebral centroids for the neutral posture to the anterior posture, subjects were able to anterior translate +101.5 mm±33.0 mm (C7-hip axis), +81.5 mm±39.2 mm (C7-S1) (vertebral centroid of C7 compared with a vertical line through the vertebral centroid of S1), and +58.9 mm±19.1 mm (T12-S1). In the anterior translated posture, disc loads and stresses were significantly increased for all levels below T9. Increases in IVD compressive loads and shear loads, and the corresponding stresses, were most marked at the L5-S1 level and L3-L4 level, respectively. The extensor muscle loads required to maintain static equilibrium in the upright posture increased from 147.2 N (mean, neutral posture) to 667.1 N (mean, translated posture) at L5-S1. Compressive loads on the anterior and posterior L5-S1 disc nearly doubled in the anterior translated posture. Anterior translation of the thorax resulted in significantly increased loads and stresses acting on the thoracolumbar spine. This posture is common in lumbar spinal disorders and could contribute to lumbar disc pathologies, progression of L5-S1 spondylolisthesis deformities, and poor outcomes after lumbar spine surgery. In conclusion, anterior trunk translation in the standing subject increases extensor muscle activity and loads and stresses acting on the intervertebral disc in the lower thoracic and lumbar regions.
The effect of posture on lumbar muscle morphometry from upright MRI
European Spine Journal, 2020
Purpose To assess the effect of upright, seated, and supine postures on lumbar muscle morphometry at multiple spinal levels and for multiple muscles. Methods Six asymptomatic volunteers were imaged (0.5 T upright open MRI) in 7 postures (standing, standing holding 8 kg, standing 45° flexion, seated 45° flexion, seated upright, seated 45° extension, and supine), with scans at L3/L4, L4/L5, and L5/S1. Muscle cross-sectional area (CSA) and muscle position with respect to the vertebral body centroid (radius and angle) were measured for the multifidus/erector spinae combined and psoas major muscles. Results Posture significantly affected the multifidus/erector spinae CSA with decreasing CSA from straight postures (standing and supine) to seated and flexed postures (up to 19%). Psoas major CSA significantly varied with vertebral level with opposite trends due to posture at L3/L4 (increasing CSA, up to 36%) and L5/S1 (decreasing CSA, up to 40%) with sitting/ flexion. For both muscle groups, radius and angle followed similar trends with decreasing radius (up to 5%) and increasing angle (up to 12%) with seated/flexed postures. CSA and lumbar lordosis had some correlation (multifidus/erector spinae L4/L5 and L5/S1, r = 0.37-0.45; PS L3/L4 left, r = − 0.51). There was generally good repeatability (average ICC(3, 1): posture = 0.81, intra = 0.89, inter = 0.82). Conclusion Changes in multifidus/erector spinae muscle CSA likely represent muscles stretching between upright and seated/flexed postures. For the psoas major, the differential level effect suggests that changing three-dimensional muscle morphometry with flexion is not uniform along the muscle length. The muscle and spinal level-dependent effects of posture and spinal curvature correlation, including muscle CSA and position, highlight considering measured muscle morphometry from different postures in spine models.
Thoracic Coupled Motions of Korean Men in Good Health in Their 20s
Journal of Physical Therapy Science, 2014
The purpose of this study was to investigate thoracic coupled motions of 20 Korean young individuals. [Methods] Thoracic motion of twenty healthy male college students aged 23.2±3.1 was examined. The coupled motions of the thoracic regions T1-4, T4-8, T8-12 were measured using a three dimensional motion capture system. [Results] Coupled axial rotation in the same direction as lateral bending was observed in T1-T4 and T4-T8 in the neutral, flexed, and extended postures of the thoracic spine. In T8-T12, coupled axial rotation in the same direction as lateral bending were observed in the neutral and flexed postures, while coupled axial rotation in the opposite direction was observed in an extended posture. [Conclusion] The patterns of coupled motions in the thoracic spine demonstrated some variability between postures and regions in vivo. However, coupled motions in the same direction were predominantly lateral flexion or axial rotation in the three postures.
Journal of Physical Therapy Science
This study determined whether the results of the mobility assessment of pelvic and thoracic rotation (static evaluation), which is often used in clinical settings, are related to step length asymmetry. Moreover, we identified the postural evaluation of rotation that may be related to gait asymmetry. [Participants and Methods] We hypothesize that a certain relationship exists between the static assessments of pelvic rotation and step length asymmetry. Fifteen healthy adult males participated in static posture and gait motion analyses using a motion-capture system. The static evaluation was analyzed using three parameters: pelvic rotation in standing, pelvic rotation with kneeling, and thorax rotation in sitting. [Results] The relationship between the asymmetric variables obtained from static evaluation and gait observations demonstrated a significant correlation. The asymmetric variables of step length and asymmetric variables of thorax rotation in sitting showed a significant relationship. Furthermore, significant correlations were found between asymmetric variables of pelvic rotation during gait and asymmetric variables of step length and between asymmetric variables of pelvic rotation during gait and asymmetric variables of thorax rotation in sitting. [Conclusion] This study revealed asymmetric relationships between thorax rotation in sitting test and step length asymmetry in the gait. Asymmetry in the thorax rotation in sitting may be caused by a gait with biased pelvic rotation.
International Journal of Spine Surgery
Background: Regional and segmental changes of the lumbar spine have previously been described as patients transition from standing to sitting; however, alignment changes in the cervical and thoracic spine have yet to be investigated. So, the aim of this study was to assess cervical and thoracic regional and segmental changes in patients with thoracolumbar deformity versus a nondeformed thoracolumbar spine population. Methods: This study was a retrospective cohort study of a single center's database of full-body stereoradiographic imaging and clinical data. Patients were ! 18 years old with nondeformed spines (nondegenerative, nondeformity spinal pathologies) or thoracolumbar deformity (ASD: PILL . 108). Patients were propensity-score matched for age and maximum hip osteoarthritis grade and were stratified by Scoliosis Research Society (SRS)-Schwab classification by PILL , SVA, and PT. Patients with lumbar transitional anatomy or fusions were excluded. Outcome measures included changes between standing and sitting in global alignment parameters: sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), pelivc tilt (PT), thoracic kyphosis, cervical alignment, cervical SVA, C2-C7 lordosis (CL), T1 slop minus CL (TS-CL), and segmental alignment from C2 to T12. Another analysis was performed using patients with cervical and thoracic segmental measurements. Results: A total of 338 patients were included (202 nondeformity, 136 ASD). After propensity-score matching, 162 patients were included (81 nondeformity, 81 ASD). When categorized by SRS-Schwab classification, all nondeformity patients were nonpathologically grouped for PILL , SVA, and PT, whereas ASD patients had mix of moderately and markedly deformed modifiers. There were significant differences in pelvic and global spinal alignment changes from standing to sitting between nondeformity and ASD patients, particularly for SVA (nondeformed: 49.5 mm versus ASD: 27.4 mm; P , .001) and PILL (20.128 versus 13.018, P , .001). With application of the Schwab classification system upon the cohort, PILL (P ¼ .040) and SVA (P ¼ .007) for severely classified deformity patients had significantly less positional alignment change. In an additional analysis of patients with segmental measurements from C2 to T12, nondeformity patients showed significant mobility of T2-T3 (À0.998 to À0.548, P ¼ .023), T6-T7 (À3.398 to À2.898, P ¼ .032), T7-T8 (À2.688 to À2.238, P ¼ .048), and T10-T11 (0.318 to 0.0978, P ¼ .006) segments from standing to sitting. ASD patients showed mobility of the C6-C7 (1.768 to 3.458, P , .001) and T11-T12 (0.988 to 0.548, P ¼ 0.014) from standing to sitting. The degree of mobility between nondeformity and ASD patients was significantly different in C6-C7 (À0.188 versus 1.698, P ¼ .003), T2-T3 (0.458 versus À0.278, P ¼ .034), and T10-T11 (0.458 versus À0.308, P ¼ .001) segments. With application of the Schwab modifier system upon the cohort, mobility was significant in the C6-C7 (nondeformed: 0.188 versus moderately deformed: 2.128 versus markedly deformed: 0.928, P ¼ .039), T2-T3 (0.458 versus À0.088 versus À0.638, P ¼ .020), T6-T7 (0.488 versus 0.368 versus À1.858, P ¼ .007), and T10-T11 (0.458 versus À0.218 versus À0.238, P ¼ .009) segments. Conclusions: Nondeformity patients and ASD patients have significant differences in mobility of global spinopelvic parameters as well as segmental regions in the cervical and thoracic spine between sitting and standing. This study aids in our understanding of flexibility and compensatory mechanisms in deformity patients, as well as the possible impact on unfused segments when considering deformity corrective surgery.
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.
Functional asymmetry of the spine in standing and sitting positions
2011
BACKGROUND: A sedentary lifestyle, together with functional asymmetry of the body, are potentially dysfunctional factors.OBJECTIVE: In this project, the authors are trying to identify the connections between a sedentary lifestyle and the amount of functional asymmetry of the spine. METHODS: Sixteen male volunteers aged 19-25 participated in the experiment. All of them were students of the University of Physical Education in Katowice. To measure trunk movement, the BTS Smart system was used. The quantity of functional asymmetry was described as a Functional Asymmetry Ratio (FAR), calculated using the trunk range of motion on the frontal and horizontal planes.RESULTS: Larger FARs values were registered in a sitting position (p＜0.01). Frontal plane functional asymmetry was greater than the asymmetry on the horizontal plane (p＜0.05) and the asymmetry of the lumbar spine exceeded that recorded for the thoracic section (p＜0.05).CONCLUSIONS: The association between a sedentary lifestyle an...
Isometric axial rotation of the trunk in the neutral posture
European Journal of Applied Physiology, 2001
The purpose of this study was to measure the torque, the magnitude of the electromyogram (EMG) signal and the phase relationship of 14 muscles during trunk axial rotation. Fifty normal healthy volunteers (27 males and 23 females) with no lower-back injury participated in the study. The subjects were seated in an upright position in the axial rotation tester (AROT) after applying surface electrodes bilaterally to the following muscles: pectoralis major, rectus abdominis, external oblique, internal oblique, latissimus dorsi, and erector spinae at T 10 and L 3 . They were stabilized from the hip down, and the shoulder harness of the AROT was applied to their shoulders. These subjects performed maximal isometric axial rotations to the left and right in a random order. The torque and 14 channels of EMG were monitored, and their magnitude, slope of the increase in magnitude, and timing of the anticipation and onset activity were determined. The results revealed that the females produced 65% of the torque of their male counterparts. The pattern and magnitude of EMG in performing these tasks were signi®cantly dierent between males and females (P<0.01). Males generated the greatest activity in their ipsilateral latissimus dorsi followed by their contralateral external oblique muscles. In the females, maximal EMG activity was observed in their contralateral pectoralis muscle. Thus, under the current experimental conditions, the females employed a dierent muscle recruitment strategy compared to the males. Each muscle involved in axial rotation was sig-ni®cantly dierent from the other (P<0.01). The timing pattern for these activities was inconsistent, implying that there is no ®xed-order phasic recruitment of the torso muscles during maximal isometric axial rotation.
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...
Effect of torso flexion on the lumbar torso extensor muscle sagittal plane moment arms
The Spine Journal, 2003
BACKGROUND CONTEXT: Accurate anatomical inputs for biomechanical models are necessary for valid estimates of internal loading. The magnitude of the moment arm of the lumbar erector muscle group is known to vary as a function of such variables as gender. Anatomical evidence indicates that the moment arms decrease during torso flexion. However, moment arm estimates in biomechanical models that account for individual variability have been derived from imaging studies from supine postures. PURPOSE: Quantify the sagittal plane moment arms of the lumbar erector muscle group as a function of torso flexion, and identify individual characteristics that are associated with the magnitude of the moment arms as a function of torso flexion. STUDY DESIGN/SETTING: Utilization of a 0.3 Tesla Open magnetic resonance image (MRI) to image and quantify the moment arm of the right erector muscle group as a function of gender and torso flexion. METHODS: Axial MRI images through and parallel to each of the lumbar intervertebral discs at four torso flexion angles were obtained from 12 male and 12 female subjects in a lateral recumbent posture. Multivariate analysis of variance was used to investigate the differences in the moment arms at different torso flexion angles, whereas hierarchical linear regression was used to investigate associations with individual anthropometric characteristics and spinal posture. RESULTS: The largest decrease in the lumbar erector muscle group moment arm from neutral to 45-degree flexion occurred at the L5-S1 level (9.7% and 8.9% for men and women, respectively). Measures of spinal curvature (L1-S1 lordosis), body mass and trunk characteristics (depth or circumference) were associated with the varying moment arm at most lumbar levels. CONCLUSIONS: The sagittal plane moment arms of the lumbar erector muscle mass decrease as the torso flexes forward. The change in moment arms as a function of torso flexion may have an impact on prediction of spinal loading in biomechanical models.