Upright Weight-bearing Position Research Articles

Acute Response to One Bout of Dynamic Standing Exercise on Blood Glucose and Blood Lactate Among Children and Adolescents With Cerebral Palsy Who are Nonambulant.

To investigate the acute exercise effects of dynamic standing exercise on blood glucose and blood lactate among children and adolescents with cerebral palsy who are nonambulant. Twenty-four participants with cerebral palsy who are nonambulant performed 30 minutes of dynamic standing exercise using a motorized device enabling assisted passive movements in an upright weight-bearing position. Capillary blood samples were taken from the fingertip for measurement of blood glucose and blood lactate at rest and at the end of exercise. At rest, the participants had hyperlactatemia that was unaffected after exercise, presented as median and interquartile range at rest 1.8 (1.3:2.7) mmol/L, and after exercise 2.0 (1.1:2.5) mmol/L. Children and adolescents with Gross Motor Function Classification System, level V, had higher lactate levels at rest (2.5 [1.8:2.9] vs 1.4 [1.0:2.0]; P = .030) and after exercise (2.3 [2.0:2.6] vs 1.2 [0.9:2.2]; P = .032) compared with children and adolescents with Gross Motor Function Classification System, level IV, respectively. A statistically significant larger decrease in blood lactate levels after exercise was observed in children and adolescents with higher resting blood lactate levels (ρ = .56; P = .004). There were no statistically significant changes in blood glucose. Forty percentage of the participants had mild hyperlactatemia at rest and participants with the highest blood lactate levels at rest had the greatest decrease in blood lactate levels after one bout of exercise. Children and adolescents who were classified with the highest level of the Gross Motor Function Classification Scale had higher blood lactate levels. More studies are needed on how to prevent chronically high resting levels of lactate with exercise in children with cerebral palsy who are nonambulant.

In vivo 3D tomography of the lumbar spine using a twin robotic X-ray system: quantitative and qualitative evaluation of the lumbar neural foramina in supine and upright position

ObjectivesSupine lumbar spine examinations underestimate body weight effects on neuroforaminal size. Therefore, our purpose was to evaluate size changes of the lumbar neuroforamina using supine and upright 3D tomography and to initially assess image quality compared with computed tomography (CT).MethodsThe lumbar spines were prospectively scanned in 48 patients in upright (3D tomographic twin robotic X-ray) and supine (30 with 3D tomography, 18 with CT) position. Cross-sectional area (CSA), cranio-caudal (CC), and ventro-dorsal (VD) diameters of foramina were measured by two readers and additionally graded in relation to the intervertebral disc height. Visibility of bone/soft tissue structures and image quality were assessed independently on a 5-point Likert scale for the 18 patients scanned with both modalities. Descriptive statistics, Wilcoxon’s signed-rank test (p < 0.05), and interreader reliability were calculated.ResultsNeuroforaminal size significantly decreased at all levels for both readers from the supine (normal intervertebral disc height; CSA 1.25 ± 0.32 cm2; CC 1.84 ± 0.24 cm2; VD 0.88 ± 0.16 cm2) to upright position (CSA 1.12 ± 0.34 cm2; CC 1.78 ± 0.24 cm2; VD 0.83 ± 0.16 cm2; each p < 0.001). Decrease in intervertebral disc height correlated with decrease in foraminal size (supine: CSA 0.88 ± 0.34 cm2; CC 1.39 ± 0.33 cm2; VD 0.87 ± 0.26 cm2; upright: CSA 0.83 ± 0.37 cm2, p = 0.010; CC 1.32 ± 0.33 cm2, p = 0.015; VD 0.80 ± 0.21 cm2, p = 0.021). Interreader reliability for area was fair to excellent (0.51–0.89) with a wide range for cranio-caudal (0.32–0.74) and ventro-dorsal (0.03–0.70) distances. Image quality was superior for CT compared with that for 3D tomography (p < 0.001; κ, CT = 0.66–0.92/3D tomography = 0.51–1.00).ConclusionsThe size of the lumbar foramina is smaller in the upright weight-bearing position compared with that in the supine position. Image quality, especially nerve root delineation, is inferior using 3D tomography compared to CT.Key Points• Weight-bearing examination demonstrates a decrease of the neuroforaminal size.• Patients with higher decrease in intervertebral disc showed a narrower foraminal size.• Image quality is superior with CT compared to 3D tomographic twin robotic X-ray at the lumbar spine.

Measurement of the quadriceps (Q) angle with respect to various body parameters in young Arab population.

The quadriceps angle (Q angle), formed between the quadriceps muscles and the patella tendon, is considered clinically as a very important parameter which displays the biomechanical effect of the quadriceps muscle on the knee, and it is also regarded a crucial factor for the proper posture and movement of the knee patella. The Q angle is routinely and regularly used as an assessment parameter during the diagnosis of many knee-related problems, including the anterior knee pain, osteoarthritis, and degenerative knee disorders. This study had been conducted so as to measure the normal Q angle values range in the Arab nationalities and determine the correlation between Q angle values and several body parameters, including gender, height, weight, dominant side, and the condylar distance of the femur. The study includes 500 healthy young Arab students from the Yarmouk University and Jordan University of Science and Technology. The Q angle of those volunteers was measured using a universal manual Goniometer with the subjects in the upright weight-bearing position. It was found that Q angle was greater in young women than young men. Also, the analysis of the data revealed an insignificant increase in the dominant side of the Q angle. In addition, the Q angle was significantly higher in the taller people of both sexes. However, the Q angle did not present any considerable correlation with weight in the study population; conversely, it was clearly observed that there was a link with the condylar distance of the femur in both sexes. It was also noticed that the Q angle increased remarkably when there was an increase in the condylar distance. Consequently, it turned out that the gender, height, and the condylar distance were momentous factors that had impact on the Q angle in our study samples. However, weight and dominancy factors did not show to have any influence on the values in our study.

Modic I changes size increase from supine to standing MRI correlates with increase in pain intensity in standing position: uncovering the \u201cbiomechanical stress\u201d and \u201cactive discopathy\u201d theories in low back pain

PurposeTo evaluate the relationship between degenerative disc, endplate Modic changes (MC) type I, and pain during upright weight-bearing MRI scan of the lumbar spine in a cohort of patients with non-specific low back pain.Materials and methodsWe evaluated 38 patients with non-specific low back pain and MRI evidence of Modic I vertebral changes. The patients were evaluated in a standard and upright weight-bearing position using a dedicated MR unit. The extent of endplate MC type I, intervertebral disc height at the involved level, and degree of degeneration in the same intervertebral disc were compared. Pain was assessed through the VAS questionnaire.ResultsIn the upright position, the area of Modic I changes increased in 26 patients (68.4%, p ≤ 0.001) compared to the supine position. In the upright position, reduction in the disc height was found in 35 patients (92.1%). Correlation analysis showed moderate negative correlation (ρ = − 0.45) between intervertebral disc height and increase in the area of Modic I changes, and weak positive correlation (ρ = 0.12) between Pfirrmann grade and increase in the area of Modic I changes. At clinical evaluation, 30 patients (78.9%) reported worsening of low back pain standing in the upright position. Increase in VAS values on the upright position correlated significantly (ρ = 0.34) with an increase in the area of Modic I changes.ConclusionsOur results showed the modifications of Modic I changes under loading, with MRI evidence of increased MC area extent in the upright position and correlation between Modic changes extension increase and increase in pain in the standing position. Weight-bearing MRI scans represent a valuable complement to standard sequences since they provide the radiologist with additional diagnostic information about low back pain.Graphical abstractThese slides can be retrieved from Electronic Supplementary Material.

3D Modeling of Lower Extremities With Biplanar Radiographs: Reliability of Measures on Subsequent Examinations.

Biplanar radiography with 3-dimensional (3D) modeling (EOS) provides a comprehensive assessment of lower limb alignment in an upright weight-bearing position with less radiation than conventional radiography. A study was performed to assess the consistency and reliability of 2 lower extremity 3D biplanar radiograph models created at least 1 year apart in a pediatric population. All patients who had 2 lower extremity radiographic evaluations with EOS performed at visits a minimum of 1 year apart were reviewed. Digital radiographs, of lower extremities in both frontal and sagittal planes, were acquired simultaneously, using the EOS system. The 3D reconstruction of the images was achieved utilizing the SterEOS software. Pelvic position, femoral and tibial anatomy, and the torsional profile were evaluated and compared using t tests. In total, 53 patients with a mean age of 11.7 years (range, 6.1 to 18.9 y) met inclusion criteria. When comparing 3D models between visits, minimal differences were noted in proximal femoral anatomy and pelvic alignment (pelvic incidence, sacral slope, sagittal tilt, neck shaft angle). Expected differences in femoral and tibial length corresponded with normal longitudinal growth between visits. Sagittal plane knee position varied widely between examinations. Femoral and/or tibial rotational osteotomies were performed in 37% of extremities between examinations. After femoral derotational osteotomy, a significant difference in femoral anteversion was appreciated when comparing preoperative and postoperative 3D models. However, this difference was less than the expected difference based on the anatomic correction achieved intraoperatively. No differences were noted in tibial torsion measures after tibial derotational osteotomy. The 3D modeling based on biplanar radiographs provides consistent and reliable measures of pelvic and hip joint anatomy of the lower extremity. Patient positioning may influence the reproducibility of knee alignment. The torsional profile assessment did not accurately reflect changes obtained by derotational osteotomy. Level III.

3D Imaging of Joints in the Upright Weight-bearing Position using Multitom Rax

3D Imaging of Joints in the Upright Weight-bearing Position using Multitom Rax

Upright weight-bearing CT of the knee during flexion: changes of the patellofemoral and tibiofemoral articulations between 0° and 120°.

To prospectively compare patellofemoral and tibiofemoral articulations in the upright weight-bearing position with different degrees of flexion using CT in order to gain a more thorough understanding of the development of diseases of the knee joint in a physiological position. CT scans of the knee in 0°, 30°, 60° flexion in the upright weight-bearing position and in 120° flexion upright without weight-bearing were obtained of 10 volunteers (mean age 33.7±6.1years; range 24-41) using a cone-beam extremity-CT. Two independent readers quantified tibiofemoral and patellofemoral rotation, tibial tuberosity-trochlear groove distance (TTTG) and patellofemoral distance. Tibiofemoral contact points were assessed in relation to the anteroposterior distance of the tibial plateau. Significant differences between degrees of flexion were sought using Wilcoxon signed-rank test (P<0.05). With higher degrees of flexion, internal tibiofemoral rotation increased (0°/120° flexion; mean, 0.5°±4.5/22.4°±7.6); external patellofemoral rotation decreased (10.6°±7.6/1.6°±4.2); TTTG decreased (11.1mm ±3.7/-2.4mm ±6.4) and patellofemoral distance decreased (38.7mm ±3.0/21.0mm ±7.0). The CP shifted posterior, more pronounced laterally. Significant differences were found for all measurements at all degrees of flexion (P=0.005-0.037), except between 30° and 60°. ICC was almost perfect (0.80-0.99), except for the assessment of the CP (0.20-0.96). Knee joint articulations change significantly during flexion using upright weight-bearing CT. Progressive internal tibiofemoral rotation leads to a decrease in the TTTG and a posterior shift of the contact points in higher degrees of flexion. This elucidates patellar malalignment predominantly close to extension and meniscal tears commonly affecting the posterior horns.

The effects of a dynamic patellar realignment brace on disease determinants for patellofemoral instability in the upright weight-bearing condition.

BackgroundPatellar stabilizing braces are used to alleviate pain and prevent subluxation/dislocation by having biomechanical effects in terms of improved patellar tracking. The purpose of this study is to analyze the effects of the dynamic patellar realignment brace, Patella Pro (Otto Bock GmbH, Duderstadt, Germany), on disease determinants in subjects with patellofemoral instability using upright weight-bearing magnetic resonance imaging (MRI).MethodsTwenty subjects (8 males and 12 females) with lateral patellofemoral instability were studied in an open-configuration magnetic resonance imaging scanner in an upright weight-bearing position at full extension (0° flexion) and 15° and 30° flexion with and without the realignment brace. Disease determinants were defined by common patellofemoral indices that included the Insall–Salvati Index, Caton–Deschamps Index, and the Patellotrochlear Index to determine patella height and patella tilt angle, bisect offset, and tuberositas tibiae–trochlear groove (TT–TG) distance to determine patellar rotation and translation with respect to the femur and the alignment of the extensor mechanism.ResultsAnalyses of variance revealed a significant effect of the brace with reduction of the three patellar height ratios, patella tilt angle, and bisect offset as well as TT–TG distance. Post hoc pairwise comparisons of the corresponding conditions with and without the realignment brace revealed significantly reduced patella height ratios, patella tilt angles, and bisect offsets at full extension and 15° and 30° flexion. No significant differences between the TT–TG distances at full extension but significant reductions at 15° and 30° flexion were observed when using the realignment brace compared to no brace.ConclusionsThis study suggests that the dynamic patellar realignment brace is capable of improving disease determinants in the upright weight-bearing condition in the range of 0° to 30° flexion in patients with patellofemoral instability.

Diagnosis of vertebral fractures using a low-dose biplanar imaging system.

Vertebral fractures (VFs) are independent risk factors for new fractures. However, spine radiographs cannot be used as a screening method. EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to vertebral fracture assessment (VFA). Vertebral fractures (VFs) are risk factors for new fractures. However, spine radiographs cannot be used as a screening method for both cost and radiation concerns. EOS® X-ray imaging system which allows the acquisition of biplane images in an upright weight-bearing position with low radiation dose was used. The objective of this study was to compare EOS® to VFA for the diagnosis of VF. We conducted a cross-sectional study in subjects aged above 50 years with indication for spine imaging. EOS® and VFA of the spine were performed the same day. Sensitivity (Se), specificity (Sp), negative predictive value (NPV), and the interobserver precision of EOS® were compared to VFA for the diagnosis of VF. Two hundred patients (mean age 66.2 years) were included. At the vertebral level, 2.4 and 3.6 % of vertebrae were not legible using EOS® and VFA, respectively (p = 0.0007). The legibility of spine was significantly affected by scoliosis (odds ratio (OR) = 2.8, p < 0.0001, for EOS®, and OR = 1.8, p = 0.0041, for VFA). Sixty-six patients (33.0 %) and 69 (34.5 %) had at least one VF using VFA and EOS®, respectively. At patient level, Se, Sp, and NPV for the diagnosis of VF of EOS® were 79.7, 91.6, and 99 %, respectively. Concordance between both observers was very good for EOS® (kappa-score = 0.89), higher than for VFA (κ = 0.67). This study shows that EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to VFA.

Upright Cone CT of the hindfoot: Comparison of the non-weight-bearing with the upright weight-bearing position

To prospectively compare computed tomography (CT) of the hindfoot in the supine non-weight-bearing position (NWBCT) with upright weight-bearing position (WBCT). Institutional review board approval and informed consent of all patients were obtained. NWBCT and WBCT scans of the ankle were obtained in 22 patients (mean age, 46.0 ± 17.1years; range 19-75years) using a conventional 64-row CT for NWBCT and a novel cone-beam CT for WBCT. Two musculoskeletal radiologists independently performed the following measurements: the hindfoot alignment angle, fibulocalcaneal and tibiocalcaneal distances, lateral talocalcaneal joint space width, talocalcaneal overlap and naviculocalcaneal distance. Significant changes between NWBCT and WBCT were sought using Wilcoxon signed-rank test. P values <0.05 were considered statistically significant. Significant differences were found for all measurements except the hindfoot alignment angle and tibiocalcaneal distance. Significant measurement results were as follows (NWBCT/WBCT reader 1; NWBCT/WBCT reader 2, mean ± standard deviation): fibulocalcaneal distance 3.6mm ± 5.2/0.3mm ± 6.0 (P = 0.006); 1.4mm ± 6.3/-1.1mm ± 6.3 (P = 0.002), lateral talocalcaneal joint space width 2.9mm ± 1.7/2.2mm ± 1.1 (P = 0.005); 3.4mm ± 1.9/2.4mm ± 1.3 (P = 0.001), talocalcaneal overlap 4.1mm ± 3.9/1.4mm ± 3.9 (P = 0.001); 4.5mm ± 4.3/1.4mm ± 3.7 (P < 0.001) and naviculocalcaneal distance 13.5mm ± 4.0/15.3mm ± 4.7 (P = 0.037); 14.0mm ± 4.4/15.7mm ± 6.2 (P = 0.100). Interreader agreement was good to excellent (ICC 0.48-0.94). Alignment of the hindfoot significantly changes in the upright weight-bearing CT position. Differences can be visualised and measured using WBCT. • Cone-beam computed tomography (CBCT) offers new opportunities for musculoskeletal problems • Visualization and quantification of hindfoot alignment are possible in upright weight-bearing CBCT • Hindfoot alignment changes significantly from non-weight-bearing to weight-bearing CT • The weight-bearing position leads to a decrease in the fibulocalcaneal distance and talocalcaneal overlap • The naviculocalcaneal distance is increased in the weight-bearing position.

Body Posture Asymmetry Differences between Children with Mild Scoliosis and Children with Unilateral Cerebral Palsy

Patients with unilateral cerebral palsy (CP) often have impaired movement coordination, reduced between-limb synchronization, and less weight bearing on the affected side, which can affect the maintenance of an upright weight-bearing position and gait. This study evaluated whether the different postural patterns of children with unilateral CP could be statistically recognized using cluster analysis. Forty-five outpatients with unilateral CP (mean age, 9 years and 5 months) and 51 able-bodied children with mild scoliosis (mean age, 9 years and 2 months) were included. One observer performed moiré topography (MT) examinations using a CQ Electronic System (Poland) device. A weight distribution analysis on the base of support (BOS) between the body sides was performed simultaneously. A force plate dynamographic platform (PDM), ZEBRIS (Germany), with FootPrint software was used for these measurements. Cluster analysis revealed three groups: Cluster 1 (n = 71, 73.96%), Cluster 2 (n = 8, 8.33%), and Cluster 3 (n = 17, 17.71%). Based on the MT parameters (extracted using a data reduction technique), three typical asymmetrical postural patterns were described: (1) the postural pattern of children with mild scoliosis (SCOL), (2) the progravitational postural pattern (PGPP), and (3) the antigravitational pattern. Patterns two and three were identified in children with unilateral CP.

Patellar Maltracking Correlates With Vastus Medialis Activation Delay in Patellofemoral Pain Patients

Background: Delayed onset of vastus medialis (VM) activity compared with vastus lateralis activity is a reported cause for patellofemoral pain. The delayed onset of VM activity in patellofemoral pain patients likely causes an imbalance in muscle forces and lateral maltracking of the patella; however, evidence relating VM activation delay to patellar maltracking is sparse. The aim of this study was to investigate the relationship between VM activation delay and patellar maltracking measures in pain-free controls and patellofemoral pain patients. Hypothesis: Patellar tilt and bisect offset, measures of patellar tracking, correlate with VM activation delay in patellofemoral pain patients classified as maltrackers. Study Design: Case control study; Level of evidence, 3. Methods: Vasti muscle activations were recorded in pain-free (n = 15) and patellofemoral pain (n = 40) participants during walking and jogging. All participants were scanned in an open-configuration magnetic resonance scanner in an upright weightbearing position to acquire the position of the patella with respect to the femur. Patellar tilt and bisect offset were measured, and patellofemoral pain participants were classified into normal tracking and maltracking groups. Results: Correlations between VM activation delay and patellar maltracking measures were statistically significant in only the patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset (R 2 = .89, P < .001, with patellar tilt during walking; R 2 = .75, P = .012, with bisect offset during jogging). There were no differences between the means of activation delays in pain-free and all patellofemoral pain participants during walking (P = .516) or jogging (P = .731). Conclusion: There was a relationship between VM activation delay and patellar maltracking in the subgroup of patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset. Clinical Relevance: A clinical intervention such as VM retraining may be effective in only a subset of patellofemoral pain participants—namely, those with excessive tilt and excessive bisect offset measures. The results highlight the importance of appropriate classification of patellofemoral pain patients before selection of a clinical intervention.

Plantar fascia evaluation with a dedicated magnetic resonance scanner in weight-bearing position: our experience in patients with plantar fasciitis and in healthy volunteers

This study assessed the usefulness of upright weight-bearing examination of the ankle/hind foot performed with a dedicated magnetic resonance (MR) imaging scanner in the evaluation of the plantar fascia in healthy volunteers and in patients with clinical evidence of plantar fasciitis. Between January and March 2009, 20 patients with clinical evidence of plantar fasciitis (group A) and a similar number of healthy volunteers (group B) underwent MR imaging of the ankle/hind foot in the upright weight-bearing and conventional supine position. A 0.25-Tesla MR scanner (G-Scan, Esaote SpA, Genoa, Italy) was used with a dedicated receiving coil for the ankle/hind foot. Three radiologists, blinded to patients' history and clinical findings, assessed in consensus morphological and dimensional changes and signal intensity alterations on images acquired in both positions, in different sequences and in different planes. In group A, MR imaging confirmed the diagnosis in 15/20 cases; in 4/15 cases, a partial tear of the plantar fascia was identified in the upright weight-bearing position alone. In the remaining 5/20 cases in group A and in all cases in group B, the plantar fascia showed no abnormal signal intensity. Because of the increased stretching of the plantar fascia, in all cases in group A and B, thickness in the proximal third was significantly reduced (p<0.0001) under upright weight-bearing compared with the supine position. Imaging the ankle/hind foot in the upright weight-bearing position with a dedicated MR scanner and a dedicated coil might enable the identification of partial tears of the plantar fascia, which could be overlooked in the supine position.

Establishment of 3-dimensional finite element model of human knee joint and its biomechanics

To establish a 3-dimensional (3-D) finite element knee model in healthy Chinese males, to verify the validity of the model, and to analyze the biomechanics of this model under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A set of consecutive transectional computerized tomography images of normal male knee joints in upright weight-bearing position was selected. With image processing and inversion technology, the 3-D finite element model of the normal knee joint was established through the software ABAQOUS/STANDARD Version-6.5.Biomechanical analysis of this model was processed under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A 3-D finite element model of healthy Chinese males was successfully established. The ranges of motion of varus and valgus were both small and the difference between them has no statistical significance (P>0.05). The motion of internal and external rotation of the knee took place only in flexion situation.The range of motion of external rotation was larger than that of internal rotation in the same knee (P<0.05). The 3-D geometrical model of the knee resembles the actual knee segments. It can imitate the knee response to different loads. This model could be used for further study on knee biomechanics.

Repeat Upright Positional Magnetic Resonance Imaging for Diagnosis of Disorders Underlying Chronic Noncancer Lumbar Pain

Objective Cases of chronic noncancer pain are both the most frequent and the most difficult that the spine care professional is called upon to treat. We use this case to illustrate the potential effectiveness of repeat positional upright, weight-bearing magnetic resonance (MR) imaging to diagnose disorders and to detect changes in disorders. Clinical Features We present the case of a 35-year-old man referred to our neurosurgical clinic with complaints of chronic, noncancer lower back pain and right-greater-than-left sciatica. Traditional recumbent MR imaging had revealed degenerative disk disease at L5-S1 and a 2.2-mm (grade 1) degenerative spondylolisthesis. The patient had not improved after more than a year of conservative treatments and, moreover, had been prescribed opiates for pain management that were potentially masking changes in his condition. Intervention and Outcomes After referral to our clinic, we ordered repeat lumbar MR imaging in an upright weight-bearing position (sitting) 14 months after the patient's recumbent MR imaging. The weight-bearing MR imaging revealed a 9.13-mm (grade 1) degenerative spondylolisthesis at L5-S1. The patient underwent arthrodesis. His leg pain and back were significantly and clinically improved. Conclusion When patients with noncancer, lower back pain worsen, fail to improve, or require opiates to manage their pain, updated clinical diagnosis including repeat positional imaging may be an effective diagnostic strategy.