Thoracic Flexibility Research Articles

Biomechanical Effects of Thoracic Flexibility and Stiffness on Lumbar Spine Loading: A Finite Element Analysis Study

ObjectiveTo determine the effects of thoracic stiffness on mechanical stress in the lumbar spine during motion. MethodsTo evaluate the effect of preoperative thoracic flexibility, stiff and flexible spine models were created by changing the material properties of ligaments and discs in the thoracic spine. Total laminectomy was performed at L4/5 in stiff and flexible models. A biomechanical investigation and finite element analysis were performed preoperatively and postoperatively. A hybrid loading condition was applied, and the range of motion (ROM) at each segment and maximum stress in the discs and pars interarticularis were computed. ResultsIn the preoperative model with the stiff thoracic spine, lumbar disc stress, lumbar ROM, and pars interarticularis stress at L5 increased. In contrast, as the thoracic spine became more flexible, lumbar disc stress, lumbar ROM, and pars interarticularis stress at L5 decreased. All L4/5 laminectomy models had increased instability and ROM at L4/5. To evaluate the effect of thoracic flexibility on the lumbar spine, differences between the stiff and flexible thoracic spine were examined: Differences in ROM and intervertebral disc stress at L4/5 in flexion between the stiff and flexible thoracic spine were respectively 0.7° and 0.0179 MPa preoperatively and 1.5° and 0.0367 MPa in the L4/5 laminectomy model. ConclusionsBiomechanically, disc stress and pars interarticularis stress decrease in the flexible thoracic spine. Flexibility of the thoracic spine reduces lumbar spine loading and could help to prevent stress-related disorders.

Relationship Between Thoracic Flexibility and Spinal Curvature During Trunk Extension in Healthy Adults

Background: Non-specific lower back pain is a common medically and economically impactful condition that affects patients’ quality of life. Purpose: This study aimed to determine the relationship between thoracic expansion and spinal curvature angle during trunk extension in healthy participants. Results: The participants comprised 24 men aged 18–21 years. The measurement items included the lateral and longitudinal diameters of the thorax, measured at the level of the xiphoid process and 10th rib, and spinal curvature angle, measured in the upright posture and trunk extension position. The difference in thoracic expansion levels during trunk extension tended to be greater in the lower thorax than in the upper thorax, with the lateral diameter higher than the longitudinal diameter. The inferior thoracic and lumbar curvatures increased with trunk extension. Regarding the relationship between the difference in thoracic expansion and the amount of change in the spinal curvature, the difference in the expiratory lateral diameter of the lower thorax during trunk extension was positively correlated with the superior thoracic curvature during trunk extension. Conclusions: These results indicate that expansion of the lower thoracic lateral diameter increased the thoracic curvature during trunk extension exercises. Consequently, the lumbar curvature may be suppressed. Reduced lower thorax flexibility may enhance lumbar curvature during trunk extension. Therefore, flexibility of the lower lateral thoracic diameter may be a factor when preventing lower back pain. KEY WORDS: Thorax, Lateral Diameter, Longitudinal Diameter, Trunk Extension, Chest Griping.

The utility of supine radiographs in the assessment of thoracic flexibility and risk of proximal junctional kyphosis.

Supine radiographs have successfully been used for preoperative planning of lumbar deformity corrections. However, they have not been used to assess thoracic flexibility, which has recently garnered attention as a potential contributor to proximal junctional kyphosis (PJK). The purpose of this study was to compare supine to standing radiographs to assess thoracic flexibility and to determine whether thoracic flexibility is associated with PJK. A retrospective study was conducted of a single-institution database of patients with adult spinal deformity (ASD). Sagittal alignment parameters were compared between standing and supine and between pre- and postoperative radiographs. Thoracic flexibility was determined as the change between preoperative standing thoracic kyphosis (TK) and preoperative supine TK, and these changes were measured over the overall thoracic spine and the fused portion of the thoracic spine (i.e., TK fused). A case-control analysis was performed to compare thoracic flexibility between patients with PJK and those without (no PJK). The cohort was also stratified into three groups based on thoracic flexibility: kyphotic change (increased TK), lordotic change (decreased TK), and no change. The PJK rate was compared between the cohorts. A total of 101 patients (mean 63 years old, 82.2% female, mean BMI 27.4 kg/m2) were included. Preoperative Scoliosis Research Society-Schwab ASD classification showed moderate preoperative deformity (pelvic tilt 27.7% [score ++]; pelvic incidence-lumbar lordosis mismatch 44.6% [score ++]; sagittal vertical axis 42.6% [score ++]). Postoperatively, the average offset from age-adjusted alignment goals demonstrated slight overcorrection in the study sample (-8.5° ± 15.6° pelvic incidence-lumbar lordosis mismatch, -29.2 ± 53.1 mm sagittal vertical axis, -5.4 ± 10.8 pelvic tilt, and -7.6 ± 11.7 T1 pelvic angle). TK decreased between standing and supine radiographs and increased postoperatively (TK fused: -25.3° vs -19.6° vs -29.9°; all p < 0.001). The overall rate of radiographic PJK was 23.8%. Comparisons between PJK and no PJK demonstrated that offsets from age-adjusted alignment goals were similar (p > 0.05 for all). There was a significant difference in the PJK rate when stratified by thoracic flexibility cohorts (kyphotic: 0.0% vs no change: 18.4% vs lordotic: 35.0%; p = 0.049). Logistic regression revealed thoracic flexibility (p = 0.045) as the only independent correlate of PJK. Half of patients with ASD experienced significant changes in TK during supine positioning, a quality that may influence surgical strategy. Increased thoracic flexibility is associated with PJK, possibly secondary to fusing the patient's spine in a flattened position intraoperatively.

Preoperative Radiographic Evaluation of Thoracic Flexibility and Compensation for Adult Spinal Deformity Surgery. How to Select Optimal Upper Instrumented Vertebra to Prevent Proximal Junctional Kyphosis.

Retrospective study of a cohort of consecutive patients. The aim of this study was to clarify the usefulness and value of the difference in thoracic kyphosis (ΔTK) angle in various positions by imaging the patient standing, prone, and supine to evaluate TK flexibility and compensation, and to establish optimal radiography to determine an appropriate thoracic level for upper instrumented vertebra (UIV) because a strategy to select an appropriate level to avoid proximal junctional kyphosis (PJK) remains elusive. Postoperative reciprocal progression of TK is a significant risk factor for PJK. However, how to predict and prevent postoperative reciprocal progression of TK remains unclear. We hypothesized that preoperative evaluation of both TK flexibility and compensation is essential to predict PJK and determine the UIV level. We included 144 consecutive patients with adult spinal deformity (ASD), ≥2 years' follow-up, and UIV Th9-11 in this retrospective cohort study. TK was measured from images with patients standing, prone, and supine. Supine ΔTK was calculated as standing TK- supine TK. Prone ΔTK was calculated as standing TK - prone TK. Receiver-operating characteristic (ROC) curves were analyzed to determine the thresholds of supine ΔTK and prone ΔTK for PJK occurrence. PJK was observed in 64 of 144 (44%) patients 2 years postoperatively. Prone and supine ΔTKs were significantly larger in patients with PJK. A significant positive correlation between prone ΔTK and supine ΔTK was observed. When data from patients with and without PJK were plotted separately, a significantly higher proportion of patients with PJK had large prone and supine ΔTKs. The cutoff values of prone and supine ΔTKs for PJK risk were determined using ROC curve analysis. Because of their significantly high risk for PJK, in patients with ASD and prone ΔTK >11.5° and supine ΔTK >18.5°, the upper-thoracic spine should be considered for UIV.Level of Evidence: 3.

A quantitative analysis model of thoracic flexibility for wearable personal protection equipment

Human body models of pose and motion are widely used in the interactive design process. Existing models, however, have examined movements of the thoracic spine independent of the ribcage, without specifically examining the influence of motion on specific thoracic areas. Additionally, current models are not widely used by designers or the industry for a variety of reasons. Consequently, the application of postural assessments in the design process may lack crucial data regarding complex yet contextually relevant body motions. To address this, we evaluated the optimal levels of thoracic flexibility for wearable personal protection equipment (WPPE). The ranges of four separate thoracic motions were measured in fifteen healthy males and females subjects using a motion capture system necessitating clusters of 92 reflective markers. A kinematic model for calculating 3D transformation and thoracic displacement over time was developed. A 60 segment thoracic map demonstrated that while ± 20° was sufficient for most frontal and lateral motions, distal to the xiphoid, 45° of flexion was required. For most rearward thoracic motions, ± 15° degrees was sufficient, but for movements involving the thorax distal to the T10 vertebra, 30° of flexion was required. The causal hypothesis for this numerical data was based on existing biomechanical literature. The quantitative analysis is a useful tool for assessing the biomechanics of body motion and supporting the industrial design process of well-fitted WPPE. We anticipate that our quantitative analysis model will be an integral aspect of any future ergonomic design interactive processes.

Effects of 6 Week Thoracic Flexibility Exercise on Balance, Gait Parameters and Fall Risk in Patients with Chronic Stroke; A randomized controlled study

본 연구는 만성 뇌졸중 환자를 대상으로 체간 유연성 운동이 앉은 자세 균형, 정적 균형, 보행 척도, 그리고 낙상 위험도에 어떠한 영향을 미치는지를 규명하고자 실시되었다. 만성 뇌졸중 참가자는 대조 그룹(12명)과 체간 유연성 운동 그룹(12명)으로 무작위로 배정되었다. 두 그룹 모두 표준 재활 치료 30분을 실시하였고, 체간 유연성 운동 그룹은 체간 유연성 운동을 일주일에 3번, 6주간 추가로 시행하였다. 모든 참가자는 체간 장애 척도, 정적 균형 능력, 보행 속도, 분당 보행 수, 그리고 낙상 위험도를 운동 전과 운동 종료 후에 평가하였다. 본 연구 결과에서 체간 유연성 운동 그룹은 대조 그룹과 비교하여 체간 장애 척도(t =-3.57, p =.002)와 보행 속도(t =-3.29, p =.003) 그리고 분당 보행 수(t =-2.77, p =.011)는 유의하게 증가하였고, 정적 균형 능력(t =5.37, p <.001)과 낙상 위험도(t =6.33, p <.001)는 유의하게 감소되었다. 또한, 체간 유연성 운동 그룹은 초기 평가와 비교하여 모든 평가 항목에서 유의하게 개선되었다(p <.05). 이상의 결과에서 6주간의 흉추 유연성 운동 후, 만성 뇌졸중 환자에게 있어 앉은 자세 균형 능력, 정적 균형 능력, 보행 척도, 그리고 낙상 위험도에서 긍정적인 효과가 나타났으며, 이후 다른 운동과 비교하여 효과를 검증하는 후속연구가 필요한 것으로 사료된다.

The Comparison of the Effect of Thoracic Flexibility Exercise and Lumbar Stabilization Exercise on Pain and Heart Rate Variability of Patients with Chronic Low Back Pain

The Comparison of the Effect of Thoracic Flexibility Exercise and Lumbar Stabilization Exercise on Pain and Heart Rate Variability of Patients with Chronic Low Back Pain

Essential lordosis revisited.

Significant correction of an adolescent idiopathic scoliosis in the coronal plane through a posterior approach is associated with hypokyphosis. Factors such as the magnitude of the preoperative coronal curve, the use of hooks, number of levels fused, preoperative kyphosis, screw density, and rod type have all been implicated. Maintaining the normal thoracic kyphosis is important as hypokyphosis is associated with proximal junctional failure (PJF) and early onset degeneration of the spine. The aim of this study was to determine if coronal correction per se was the most relevant factor in generating hypokyphosis. A total of 95 patients (87% female) with a median age of 14 years were included in our study. Pre- and postoperative radiographs were measured and the operative data including upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), metal density, and thoracic flexibility noted. Further analysis of the post-surgical coronal outcome (group 1 < 60% correction and group 2 ≥ 60%) were studied for their association with the postoperative kyphosis in the sagittal plane using univariate and multivariate logistic regression. Of the 95 patients, 71.6% (68) had a thoracic correction of > 60%. Most (97.8%) had metal density < 80%, while thoracic flexibility > 50% was found in 30.5% (29). Preoperative hypokyphosis (< 20°) was present in 25.3%. A postoperative thoracic hypokyphosis was four times more likely to occur in patients with thoracic correction ≥ 60% (odds ratio (OR) 4.08; p = 0.005), after adjusting for confounding variables. This association was not affected by metal density, thoracic flexibility, LIV, UIV, age, or sex. Our study supports the 'essential lordosis' hypothesis of Roaf and Dickson, i.e. with a greater ability to translate the apical vertebra towards the midline, there is a commensurate lengthening of the anterior column due to the vertebral wedging. Cite this article: Bone Joint J 2020;102-B(4):513-518.

Cervical Supine Side-Bending versus Cervical Supine Traction Radiographs: Which Is Better in Predicting Proximal Thoracic Flexibility for Lenke 1 and 2 Adolescent Idiopathic Scoliosis?

Study DesignProspective cohort study.PurposeThis study compared cervical supine side-bending (CSSB) and cervical supine traction (CST) radiographs to assess the flexibility and predict the correctability of the proximal thoracic (PT) curve for patients with adolescent idiopathic scoliosis (AIS) classified as Lenke 1 and 2.Overview of LiteratureKnowledge of the flexibility of the PT curve is crucial in the management of patients with AIS. There are no reports comparing CSSB and CST radiographs to assess this parameter.MethodsThirty patients with Lenke 1 and 2 AIS scheduled for posterior spinal fusion surgery were recruited. A standing whole spine radiography and physician-supervised CSSB and CST radiographies were performed. Patient demographic and radiological parameters were recorded, including age, gender, weight, height, body mass index, PT angle, main thoracic angle, CSSB PT angle, CST PT angle, and postoperative PT angle. From the data collected, the curve flexibility and curve correction index were calculated and compared.ResultsCSSB had a significantly (p <0.05) smaller PT angle (16.6°±10.4°) in comparison to CST (23.7°±10.7°). CSSB had significantly (p <0.05) greater flexibility (44.2%±19.7%) in comparison to CST (19.5%±18.1%). The CSSB correction index (1.2±0.9) was significantly closer to 1 in comparison to the CST correction index (4.4±5.3). There was no difference (p =0.72) between the CSSB PT angle (16.6°±10.4°) and the postoperative PT angle (16.1°±7.5°). However, the CST PT angle (23.7°±10.7°) was significantly (p <0.05) larger than the postoperative PT angle (16.1°±7.5°).ConclusionsCSSB radiographs were better for demonstrating PT flexibility and more accurately predicted correctability in comparison to the CST radiographs.

The value of sitting radiographs: analysis of spine flexibility and its utility in preoperative planning for adult spinal deformity surgery.

Sitting radiographs are a valuable tool to consider the thoracic compensatory mechanism in patients who are candidates for thoracolumbar correction surgery.

Using the spirometry to indicate respiratory exercises for elderly with Parkinson’s disease

Abstract Introduction: Respiratory dysfunction is the main cause of death in Parkinson's disease (PD) patients and bronchoaspiration pneumonia is the most common clinical respiratory complication. Objective: To assess respiratory function of elderly with PD in mild to moderate phase of the disease. Methods: A cross-sectional study was carried. Elderly in 2 to 3 PD Hoehn &amp; Yahr stage have participated. A single researcher has evaluated maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), thoracoabdominal amplitude, forced vital capacity (FVC) and expiratory volume in the first second (FEV1). Results: Sixty elderly have participated and their all spirometry and manovacuometry parameters presented significant differences (p &lt; 0.05) comparing with predicted values, except for FVC (p = 0.25). Only umbilical level did not reach normal values on cirtometry parameters. Patients classified as a restrictive disorder presented significant decrease in thoracic expandability. However the participants classified as an obstructive disorder showed significant decrease in expiratory muscle strength and peak expiratory flows. Conclusion: Elderly in mild or moderate phase of PD presented reduction in respiratory parameters. Spirometry showed to be an important tool to evaluate respiratory function and to indicate the modality of respiratory exercise. Our results suggest the indication of thoracic flexibility exercises for patient with PD classified as restrictive disorder and strength exercise of respiratory muscles for those classified as obstructive disorder.

Evaluation of the Head Kinematics of the Q3 Model and a Modified Q3 Model by Means of Crash Reconstruction

Objective: One objective of this study is to evaluate the head kinematics of the Q3 model. Another objective is to evaluate the effect on head kinematics of increased thoracic spine flexibility; more humanlike mass distribution; and more humanlike body geometry in the Q3 model. The evaluations were based on the head kinematics of children deduced from real crashes and on new data of mass distribution and updated body dimensions for 3-year-olds. Methods: The head kinematics of the Q3 model was evaluated by comparing the Q3 model's head displacement response with the deduced response of 3-year-old children in real crashes. To do so, data from crashes were collected. The data were used to develop the mathematical vehicle and restraint system models (MADYMO, TASS, the Netherlands). Three crashes involving 3-year-old children in frontal impacts were reconstructed. The models were run 35 times each (one model per crash), each time with a different setting to each of the variables for which the exact value was not known. Examples of those variables include crash pulse, initial dummy position, and initial seat belt position. Two versions of the Q3 model were used: one that correlated with the Q3 ATD and one that was modified regarding anthropometry and thoracic flexibility. The basis for the updated anthropometry was new data regarding characteristic dimensions and mass distribution collected at a Swedish hospital. Results: In the anthropometry study, 26 children were measured. The main differences between the average of the measured children and the Q3 model were found in the mass distribution of the torso and thighs: the Q3's pelvis was too heavy and the thorax, abdomen/lumbar spine, and thighs were too light. Another difference was identified in the buttock–knee length. Two of the 3 reconstructed crashes had confirmed head impacts. The Q3 model responded with head kinematics that reflected the deduced courses of events for the real children in one of 3 crashes (the one without head impact). The modified Q3 model reflected the real children in 2 of 3 crashes. Conclusions: In high-severity, straight frontal crashes, the Q3 model predicted non-head impact adequately. However, in oblique frontal crashes, the Q3 model did not sufficiently predict the head impacts. The modified Q3 model predicted the head impacts better than the Q3 model did. Greater flexibility of the thorax and redistributed mass made a positive difference regarding the head kinematics.

Direct Vertebral Body Derotation, Thoracoplasty, or Both

Prospective, longitudinal cohort (nonrandomized). To compare thoracoplasty (Th), direct vertebral body derotation (DVBD), and Th and DVBD with respect to correction of the rib prominence and Scoliosis Research Society (SRS) self-image scores in patients undergoing surgery for adolescent idiopathic scoliosis (AIS). Rib prominence correction is one of the main goals of AIS surgery. Th and DVBD are powerful tools for correction of the rib prominence; however, a paucity of literature exists comparing Th, DVBD, and Th and DVBD. A prospective longitudinal database was queried to identify patients with AIS who underwent a posterior spinal fusion with pedicle screws and 2 years of follow-up. A total of 326 patients were identified and divided into 3 groups: (1) Th alone (N = 47), (2) DVBD alone (N = 196), and (3) both Th and DVBD (N = 83). Patients were subdivided into categories on the basis of their preoperative inclinometer reading: (1) ≤9° (mild), (2) 10 to 15° (moderate), and (3) ≥ 16° (severe). Pre- and postoperative inclinometer readings and SRS self-image scores were compared using analysis of variance. Overall, the groups were similar preoperatively except for the DVBD group having higher percentage of thoracic flexibility. The preoperative rib prominence values were Th = 13.2, DVBD = 14.0, and Th and DVBD = 12.9 (P = 0.27). Taken collectively, the postoperative 2-year inclinometer readings were similar for all 3 groups (Th = 5.2, DVBD = 7.0, Th and DVBD = 5.6; P = 0.66). However, the SRS-22 self-image scores were significantly better for patients having both Th and DVBD (Th = 3.37, DVBD = 3.44, Th and DVBD = 3.76; P < 0.01). When patients were stratified by severity of preoperative rib prominence, all patients with mild prominences achieved similar corrections, although SRS self-image scores were highest in the Th and DVBD group. In patients with larger rib prominences, the addition of Th was necessary for optimal rib prominence correction, but there was no difference in SRS-22 self-image scores. Our results suggest that Th alone, DVBD alone, or both Th and DVBD provide equivalent inclinometer results in patients with mild preoperative rib prominences (≤ 9°), but higher SRS-22 self-image scores are achieved using both Th and DVBD. For larger rib prominences, better inclinometer readings are achieved with Th, although SRS-22 self-image scores are comparable.

腱板，肩甲骨機能および胸鎖関節のmobilityに対する 胸郭ストレッチの重要性

腱板，肩甲骨機能および胸鎖関節のmobilityに対する 胸郭ストレッチの重要性

Selective fusion in adolescent idiopathic scoliosis

Selective fusion in adolescent idiopathic scoliosis

Effects of Thoracic Spinal Exercise Program in VDT Workers: Pain Relief and Increased Flexibility

2 ) Objectives: The purpose of this study of the Thoracic Spinal Exercise Program was to evalu - ate its effects on VDT workers. These effects were found to include a decrease thoracic kypho - sis, increase thoracic spine mobility and decrease in the VAS (visual analog scale). These mea - sures provide a means of assessing the muscle endurance and muscle strength of the subjects. Methods: This study was conducted during the period from July 1 to August 31, 2003, and involved 58 VDT workers belonging to a company located in Seoul who were working seated in front of a computer for most of the day. After applying the thoracic exercise program, we examined the changes in the of thoracic kyphosis angle, spinal length (C7-S3), TFED (thoracic flexibility in the extension direction), MEBH (maximal elevation with both hands in the over - head direction) and CE (chest expansion). Results: Obtained from this study are as follows. 1. A significant reduction in the VAS was observed in the exercise group (pre-exercise 5.90 ±0.88 points, post-exercise 4.23±0.82 points), as compared with the control group (pre-exer - cise 6.00±0.90 points, post-exercise 5.93±0.81 points). 2. A significant reduction in thoracic kyphosis (pre-exercise 36.97±7.49, post-exercise 31.83 ±5.90) and a significant increase in thoracic flexibility in the extension direction (pre-exercise 7 . 4 7±2.30, post-exercise 11.77±3.65) were observed in the exercise group. The thoracic