scholarly journals An Enhanced Planar Linked Segment Model for Predicting Lumbar Spine Loads during Symmetric Lifting Tasks

2020 ◽  
Vol 10 (19) ◽  
pp. 6700
Author(s):  
Pietro Picerno

The present technical note aimed at enriching the planar linked segment model originally proposed by Chaffin with the prediction of the moment arm and of the orientation of the line of action of the back extensor muscles during symmetric lifting tasks. The prediction equations proposed by van Dieen and de Looze for their single equivalent muscle model were used for such a purpose. Their prediction was based on the thorax-to-pelvis flexion angle as computed from 3D video-based motion capture. In order to make these prediction equations compliant with a two-dimensional analysis, the planar angle formed by the segment joining L5/S1 to the shoulder with the longitudinal axis of the pelvis was introduced. This newly computed planar trunk flexion angle was used to feed van Dieen and de Looze’s equations, comparing the results with the original model. A full-body Plug-in-Gait model relative to 10 subjects performing manual lifting activities using a stoop and a squat technique was used for model validation. A strong association was found between the proposed planar trunk flexion angle and that used by van Dieen and de Looze (r = 0.970). A strong association and a high level of agreement were found between the back extensor muscle moment arm (r = 0.965; bias < 0.001 m; upper limit of agreement (LOA) = 0.002 m; lower LOA < 0.001 m) and the orientation of the line of action (r = 0.970; bias = 2.8°; upper LOA = 5.3°; lower LOA = 0.2°) as computed using the two methods. For both the considered variables, the prediction error fell within the model sensitivity.

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Alicja Rutkowska-Kucharska ◽  
Katarzyna Wysocka ◽  
Sławomir Winiarski ◽  
Agnieszka Szpala ◽  
Małgorzata Sobera

The aim of this research was to determine the features of a step workout technique which may be related to motor system overloading in step aerobics. Subjects participating in the research were instructors (n=15) and students (n=15) without any prior experience in step aerobics. Kinematic and kinetic data was collected with the use of the BTS SMART system comprised of 6 calibrated video cameras and two Kistler force plates. The subjects’ task was to perform basic steps. The following variables were analyzed: vertical, anteroposterior, and mediolateral ground reaction forces; foot flexion and abduction and adduction angles; knee joint flexion angle; and trunk flexion angle in the sagittal plane. The angle of a foot adduction recorded for the instructors was significantly smaller than that of the students. The knee joint angle while stepping up was significantly higher for the instructors compared to that for the students. Our research confirmed that foot dorsal flexion and adduction performed while stepping up increased load on the ankle joint. Both small and large angles of knee flexion while stepping up and down resulted in knee joint injuries. A small trunk flexion angle in the entire cycle of step workout shut down dorsal muscles, which stopped suppressing the load put on the spine.


Author(s):  
Kyoung-sim Jung ◽  
Jin-hwa Jung ◽  
Tae-sung In

The purpose of this study was to investigate the effects of cross-legged sitting on the trunk flexion angle, pelvic obliquity, and gluteal pressure of subjects with and without low back pain (LBP). The study subjects were 30 LBP patients and 30 healthy individuals. They were instructed to sit on a chair, the height of which was adjustable, so that their knee and hip joints were bent at 90°. All subjects were asked to perform two sitting postures: erect sitting and cross-legged sitting. Trunk flexion angle and pelvic obliquity were measured using a three-dimensional motion-capture system, and gluteal pressure was measured using a force plate. Compared to erect sitting, cross-legged sitting showed a significantly lower trunk flexion angle and greater pelvic obliquity in both groups. Compared to healthy subjects, the patients with LBP had lower trunk flexion angles and greater gluteal pressure asymmetry during cross-legged sitting. The pelvic obliquity was greater in the cross-legged sitting posture than in the erect sitting posture, but there was no difference between the groups. We found that the trunk became more slouched in the cross-legged sitting posture than in the erect sitting posture, and this tendency was more pronounced in patients with LBP.


2020 ◽  
Vol 133 (2) ◽  
pp. 530-537 ◽  
Author(s):  
Vivek Sudhakar ◽  
Jerusha Naidoo ◽  
Lluis Samaranch ◽  
John R. Bringas ◽  
Russell R. Lonser ◽  
...  

OBJECTIVETo develop and assess a convective delivery technique that enhances the effectiveness of drug delivery to nonspherical brain nuclei, the authors developed an occipital “infuse-as-you-go” approach to the putamen and compared it to the currently used transfrontal approach.METHODSEleven nonhuman primates received a bilateral putamen injection of adeno-associated virus with 2 mM gadolinium-DTPA by real-time MR-guided convective perfusion via either a transfrontal (n = 5) or occipital infuse-as-you-go (n = 6) approach.RESULTSMRI provided contemporaneous assessment and monitoring of putaminal infusions for transfrontal (2 to 3 infusion deposits) and occipital infuse-as-you-go (stepwise infusions) putaminal approaches. The infuse-as-you-go technique was more efficient than the transfrontal approach (mean 35 ± 1.1 vs 88 ± 8.3 minutes [SEM; p < 0.001]). More effective perfusion of the postcommissural and total putamen was achieved with the infuse-as-you-go versus transfronatal approaches (100-µl infusion volumes; mean posterior commissural coverage 76.2% ± 5.0% vs 32.8% ± 2.9% [p < 0.001]; and mean total coverage 53.5% ± 3.0% vs 38.9% ± 2.3% [p < 0.01]).CONCLUSIONSThe infuse-as-you-go approach, paralleling the longitudinal axis of the target structure, provides a more effective and efficient method for convective infusate coverage of elongated, irregularly shaped subcortical brain nuclei.


2011 ◽  
Vol 26 (3) ◽  
pp. 250-256 ◽  
Author(s):  
Brad Hendershot ◽  
Babak Bazrgari ◽  
Khoirul Muslim ◽  
Nima Toosizadeh ◽  
Maury A. Nussbaum ◽  
...  

2012 ◽  
Vol 15 (02) ◽  
pp. 1250012 ◽  
Author(s):  
Emily M. Miller ◽  
Babak Bazrgari ◽  
Maury A. Nussbaum ◽  
Michael L. Madigan

Gender, lifting loads, and flexed trunk postures are three risk factors associated with low back pain. Previous studies have not found gender differences in effective trunk stiffness (intrinsic stiffness plus reflex response) using force perturbations, but these measures may have been confounded by differences in trunk kinematics between males and females. The purpose of this study was to investigate the effects of gender, trunk extensor preload, and trunk flexion angle on intrinsic trunk stiffness using position perturbations, which have the potential to eliminate kinematic differences between research subjects and to separate intrinsic stiffness from reflex responses. A total of 13 males and 12 females were exposed to sudden, small trunk flexion position perturbations with two trunk extension preloads (0 and 30% maximum) and three trunk flexion angles (0, 20, and 40 degrees). Data collected during position perturbations were used along with a two degree of freedom model of the trunk and connecting elements to estimate intrinsic trunk stiffness. Intrinsic stiffness was lower in females compared to males, and increased with increasing preload and trunk flexion angle. Intrinsic stiffness increased more substantially among males with increasing preload and trunk angle, and effects of trunk angle were diminished with a preload. A lower intrinsic stiffness and smaller increases with preload and trunk angle, may contribute to the increased rate of occupational LBP and injury among females.


2021 ◽  
Vol 78 ◽  
pp. 102817
Author(s):  
Anna Warrener ◽  
Robert Tamai ◽  
Daniel E. Lieberman

2021 ◽  
Author(s):  
Renato Serquiz Elias Pinheiro ◽  
Emanuelly da Costa Nobre Soares ◽  
Maria Eduarda Bezerra Figueiredo ◽  
Stella Mandu Cicco

Context: Pisa Syndrome (PS) is a rare postural disorder, characterized by dystonia of the trunk muscles, lateral deviation as well as rotation of the axial axis. There is a strong association with Parkinson’s disease (PD) due to the possible imbalance between neurotransmitters. It happens either due to a decrease in dopaminergic stimuli, either because of an excess of cholinergic stimuli or drugs (an example of antidopaminergics). The diagnosis is clinical, showing at least a 10-degree trunk flexion with improvement of pharmacological and non- pharmacological measures. Case report: A 60-year-old man was diagnosed with PD five years ago due to tipical clinical complaints and physical examination. The treatment recquired an increase of Pramipexole as well as the use of Levodopa and Benserazide. After two years, he complained about neck pain, low back pain, hip pain and a slight trunk twisting. After six months, his pain was worse and he reported right hemidystonia. Thus, he was diagnosed with PS associated with PD. It was decided to optimize the therapy with Pregabalin, muscle relaxants and rehabilitation. However, it did not show any good result. In 2020, the application of botulinum toxin (BTX) evidenced excellent results, improving both the pain and the spasticity of the patient. Conclusions: Early recognition is necessary to introduce the right treatment as soon as possible, especially BTX and rehabilitation, ensuring functionality and avoiding negative outcomes.


2014 ◽  
Vol 20 (2) ◽  
pp. 186-191
Author(s):  
Alana Maria Ferreira Guimarães Bastos ◽  
Carolina Souza Neves da Costa ◽  
Nelci Adriana Cicuto Ferreira Rocha

In a child's daily routine, sit-to-stand (STS) is a prerequisite activity for many functional tasks. The relationship between gait and other abilities has been pointed out by many authors, but there is no study investigating the changes in STS during gait acquisition in children. The purpose of this study was to analyse, in healthy children, changes that occur in STS performance during gait acquisition. Five healthy children were initially assessed with an average age of 13.6 months. The kinematics in STS movement performance of the children was evaluated longitudinally during different periods of walking experience: children who have not acquired independent walking, 8.2 (±8.4) days of independent walking experience, and 86.2 (±8.7) days of independent walking experience. At the gait acquisition period we found a significant decrease in the final trunk flexion angle and an increase in amplitude of the trunk flexion. The walking experience may have changed the execution of the STS movement.


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