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Jack P. Callaghan - One of the best experts on this subject based on the ideXlab platform.
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The impact of office chair features on Lumbar lordosis, intervertebral joint and sacral tilt angles: a radiographic assessment
Ergonomics, 2016Co-Authors: Diana De Carvalho, Diane E. Grondin, Jack P. CallaghanAbstract:AbstractBackground: The purpose of this study was to determine which office chair feature is better at improving spine posture in sitting. Method: Participants (n = 28) were radiographed in standing, maximum flexion and seated in four chair conditions: control, Lumbar Support, seat pan tilt and backrest with scapular relief. Measures of Lumbar lordosis, intervertebral joint angles and sacral tilt were compared between conditions and sex. Results: Sitting consisted of approximately 70% of maximum range of spine flexion. No differences in Lumbar flexion were found between the chair features or control. Significantly more anterior pelvic rotation was found with the Lumbar Support (p = 0.0028) and seat pan tilt (p
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Spine Posture and Discomfort During Prolonged Simulated Driving With Self-Selected Lumbar Support Prominence
Human factors, 2015Co-Authors: Diana E. De Carvalho, Jack P. CallaghanAbstract:Objective:We examined magnitude preference, subjective discomfort, and spine posture during prolonged simulated driving with a self-selected amount of Lumbar Support.Background:The general use of l...
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Influence of automobile seat Lumbar Support prominence on spine and pelvic postures: a radiological investigation.
Applied ergonomics, 2012Co-Authors: Diana E. De Carvalho, Jack P. CallaghanAbstract:Abstract Background The use of Lumbar Supports has been associated with decreased reports of low back pain during driving exposures. However, there has been limited work investigating whether Lumbar Supports actually change spine and pelvic postures at the level of the vertebrae. Purpose To investigate the effectiveness of a Lumbar Support in changing radiological measures of Lumbar spine and pelvic postures and to examine the impact of Support excursion magnitudes on these postures. Methods Eight male subjects were recruited with no history of back injury, pathologies or low back pain within the past 6 months. Radiographs were taken in four postures: standing, and sitting with 0 cm, 2 cm and 4 cm Lumbar Support prominence (LSP). Results Lumbar lordosis angle increased from 20° with no Support to 25° with 2 cm Support and 30° with 4 cm Support. Lumbar lordosis angles were significantly different between 0 cm Support and 4 cm Support (p 0.001) with the exception of L1/L2 in 4 cm Support (p = 0.1381) and L5/S1 for all seated postures (p = 0.0687). All measures of pelvic posture were significantly different in sitting compared to standing (p Conclusions Lumbar Supports were shown to impact the vertebral rotations of the Lumbar spine yet had no effect on pelvis postures. Increasing Support from the current maximum of 2 cm–4 cm resulted in increased Lumbar lordosis. The changes were mostly imparted at the upper Lumbar spine joints with the most marked change being exhibited at the approximate level of the Lumbar Support apex: in the L2/L3 joint.
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The effect of an active Lumbar system on the seating comfort of officers in police fleet vehicles.
International journal of occupational safety and ergonomics : JOSE, 2009Co-Authors: Cyril J. Donnelly, Jack P. Callaghan, Jennifer L. DurkinAbstract:The purposes of this study were to determine which seat features/occupational demands contributed to police officer discomfort and whether an automobile seat fitted with an active Lumbar system (ALS) could reduce driving discomfort. Fifty-eight officers were given questionnaires to assess driving discomfort. High discomfort levels were associated with computer use, duty belt, sidearm/radio, body armour and Lumbar Support interface. Discomfort was highest in the Lumbar, sacrum, upper pelvis and mid-back regions. Twelve officers spent one shift each in a police vehicle seat and an ALS seat. Discomfort was assessed every 2 h during 8-h shifts. Reduced discomfort was reported with the ALS seat. Three Lumbar Support features, the duty belt, and the Lumbar and right upper pelvis regions, showed reduced discomfort. Overall seat discomfort decreased by 47% after 8 h of exposure to the ALS. Modifying the automobile seat helps to reduce officer discomfort during prolonged vehicle usage.
Bjorn Stromqvist - One of the best experts on this subject based on the ideXlab platform.
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Lumbar orthosis with unilateral hip immobilization effect on intervertebral mobility determined by roentgen stereophotogrammetric analysis
Spine, 1993Co-Authors: Paul Axelsson, Ragnar Johnsson, Bjorn StromqvistAbstract:To determine the additional stabilizing effect of unilateral hip fixation on external Lumbar Supports, nine patients with a posterolateral lumbosacral fusion without internal fixation were examined by roentgen stereophotogrammetric analysis. The roentgen stereophotogrammetric analysis was performed with the patients in supine and erect positions 1 month after surgery, that is, before fusion consolidation. Each patient was examined without Lumbar Support and with a molded, rigid thoracolumbosacral orthosis with extension to one thigh, thus immobilizing one hip. The additional hip immobilization had no consistent or significant stabilizing effect on the sagittal, vertical, or transverse intervertebral translations in the lower Lumbar spine. This study using roentgen stereophotogrammetric analysis gave no Support for including hip immobilization when using Lumbar orthoses after spinal fusion in patients adequately cooperating to minimize gross body motions.
Agnes Hubner - One of the best experts on this subject based on the ideXlab platform.
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influence of elastic Lumbar Support belts on trunk muscle function in patients with non specific acute Lumbar back pain
PLOS ONE, 2019Co-Authors: Christoph Anders, Agnes HubnerAbstract:Background A well-known Supportive treatment for acute nonspecific back pain, elastic back Support belts, are valued for their ability to accelerate natural self-healing, but there are concerns of a deconditioning effect due to their reliance on passive stabilization. Methods To evaluate the systematic effects of elastic abdominal belts on the trunk musculature, a total of 36 persons with acute Lumbar back pain (no longer than one week) were divided into two groups: an abdominal belt wearing group (B) and a non-abdominal belt wearing control group (C). All were examined over a period of three weeks at three time points: T1 just after assignment, T2 one week later, and T3 further two weeks later. Surface EMG (sEMG) was used to record trunk muscle activation when walking on a treadmill at walking speeds of 2, 3, 4, 5, and 6 km/h. Similarly, pain intensity (VAS) and functional impairment (ODI) over time were recorded in both groups. Results Over the observation period, a slight advantage for decreased pain intensity (C: p<0.05 T2 vs. T1; B: p<0.01 T2 vs. T1, p<0.05 T3 vs. T1) and decreased functional impairment (Cohen's d vs. T1, C: T2 0.45, T3 0.86; B: T2 1.1, T3 1.0) was observed for the belt group. For the belt group both oblique abdominal muscles exhibited significantly lower sEMG throughout the observation period (external abdominal oblique muscle: (T1), T2, (T3), internal abdominal oblique muscle: T1, (T2), (T3)) and the sEMG for the back muscles ranged from unchanged to slightly elevated for this group, but never reached statistical significance. Discussion The reduced abdominal amplitude levels in the belt group likely result from the permanent elastic stabilization provided by the belt: the required elevated intra-abdominal pressure to enhance spinal stability is then provided by lessened abdominal muscle activity complemented by the belt’s elastic Support. With regard to the back muscles, the belt, due to its movement-restricting effect, tends to activate the paravertebral musculature. In this respect, the effect of elastic abdominal belts on the trunk muscles is not uniform. Therefore, the present results suggest that the effect of elastic abdominal belts appears to be more of a temporary neutral alteration of trunk muscle coordination, with some trunk muscles becoming more active and others less, and not a case of uniform deconditioning as is suspected.
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Influence of elastic Lumbar Support belts on trunk muscle function in patients with non-specific acute Lumbar back pain
2019Co-Authors: Christoph Anders, Agnes HubnerAbstract:BackgroundA well-known Supportive treatment for acute nonspecific back pain, elastic back Support belts, are valued for their ability to accelerate natural self-healing, but there are concerns of a deconditioning effect due to their reliance on passive stabilization.MethodsTo evaluate the systematic effects of elastic abdominal belts on the trunk musculature, a total of 36 persons with acute Lumbar back pain (no longer than one week) were divided into two groups: an abdominal belt wearing group (B) and a non-abdominal belt wearing control group (C). All were examined over a period of three weeks at three time points: T1 just after assignment, T2 one week later, and T3 further two weeks later. Surface EMG (sEMG) was used to record trunk muscle activation when walking on a treadmill at walking speeds of 2, 3, 4, 5, and 6 km/h. Similarly, pain intensity (VAS) and functional impairment (ODI) over time were recorded in both groups.ResultsOver the observation period, a slight advantage for decreased pain intensity (C: p
Thomas M. Cook - One of the best experts on this subject based on the ideXlab platform.
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Lumbar Support thickness: effect on seated buttock pressure in individuals with and without spinal cord injury.
Physical therapy, 1992Co-Authors: Richard K. Shields, Thomas M. CookAbstract:We compared the effects of different Lumbar Support thicknesses on seated buttock pressure in individuals with and without spinal cord injury (SCI). Eighteen subjects with SCI (SCI group) and 18 subjects without SCI (control group) were seated on a pressure-sensing transducer incorporated into an adjustable chair. The output was calibrated so that eight pressure intervals (colors) were displayed. The Lumbar Support thickness was adjusted to 0, 2.5, 5, and 7.5 cm, and the highest and lowest seated buttock pressures were analyzed. External measurements of the hip angle were taken for each Lumbar Support condition. High reliability of repeated seated test positions was found (intraclass correlation coefficient = .93). The 5- and 7.5-cm-thick Lumbar Supports caused a decrease in the highest pressure areas in the control group, but no change in the SCI group. The hip angle was increased with each increment in Lumbar Support thickness in both groups, but the SCI group's hip angle was consistently less than that of the control group for each Lumbar Support condition. The results of this study suggest that in individuals with chronic paralysis (greater than or equal to 3 years), the use of a wheelchair Lumbar Support has a negligible effect on seated buttock pressure.
Kuen-horng Tsai - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the effect of different sitting assistive devices in reclining wheelchair on interface pressure
Biomedical engineering online, 2017Co-Authors: Kuo Yuan Huang, Yen Nien Chen, Chien Feng Kung, Yen Ting Tseng, Kuen-horng TsaiAbstract:Reclining wheelchair users often add one or more sitting assistive devices to their wheelchairs, but the effect of these additional sitting assistive devices on the risk of pressure ulcers has rarely been investigated. This study examined the four modes of reclining wheelchair without and with different sitting assistive devices, namely the back reclined mode, the Lumbar Support with back reclined mode, the femur upward with back reclined mode, and the Lumbar Support with femur upward with back reclined mode, in terms of their effects on human-wheelchair interface pressure. This study recruited 16 healthy participants to undergo the aforementioned four modes in random order and have their human-wheelchair interface pressure measured. The initial setting of experimental reclining wheelchair backrest was pushed backward to reach a 150° recline. The data on interface pressure were collected for 5 s while the participant maintained a stable sitting position. The contact area, average pressure, and peak pressure on the back area, ischial area, and femur area were recorded and calculated. Among all tested modes, the Lumbar Support with femur upward with back reclined mode provided the most significant reduction in stress load on the ischial area (P ≤ 0.010) and shifted part of the load to the femur area (P ≤ 0.009). This study quantified the effects of and differences between various reclining wheelchair–sitting assistive device combination modes. These findings are useful for the decision-making processes of rehabilitation physicians, wheelchair users, and manufacturers.
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Evaluation of a novel wheelchair sitting concept on spinal-pelvic angles
2015 E-Health and Bioengineering Conference (EHB), 2015Co-Authors: Yen Ting Tseng, Ren-yuan Shih, Kuen-horng TsaiAbstract:Excessively long wheelchair sitting has caused low back pain. This study was investigating the biomechanical effects of adjusting femoral, pelvic and Lumbar Supports during wheelchair sitting. The Lumbar angles and pelvic angles were investigated using kinetic angle measurements system. Thirty participants with no known low back pain history were tested. The research results revealed that when Lumbar and pelvic Supports were simultaneously employed with the thickness of the Supports remaining the same, the Lumbar angle is closer to the angle in standing and the pelvic angle resembles the upright sitting angle in comparison with the other two Support conditions. In conclusions, sitting with femoral Support, pelvic Support and Lumbar Support, the pelvic and Lumbar angles was fit for the user of wheelchair, which could potentially reduce low back pain.
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The effects of backward adjustable thoracic Support in wheelchair on spinal curvature and back muscle activation for elderly people
PloS one, 2014Co-Authors: Yen Nien Chen, Chih Han Chang, Kuen-horng TsaiAbstract:Objectives To investigate the effects of backward adjustable thoracic Support on spinal curvature and back muscle activation during wheelchair sitting. Methods Twenty elderly people were recruited for this study. The backward adjustable thoracic Support sitting posture was compared with the slumped, normal, and Lumbar Support sitting postures. Spinal curvatures (pelvic, Lumbar, and thoracic angles) and muscle activations of 4 back muscles on both sides (maximal voluntary isometric contraction of the Lumbar multifidus, Lumbar erector spinae, iliocostalis lumborum pars thoracis, and thoracic erector spinae at T9) were measured and compared between the different sitting postures using one-way analysis of variance with repeated measures. Results The backward adjustable thoracic Support sitting posture showed a relatively neutral pelvic tilt (−0.32±4.80°) when compared with the slumped (22.84±5.27°) and Lumbar Support (−8.97±3.31°) sitting postures (P
