Background: Low back pain is highly prevalent in the general population and is even reported as early as at primary school. A poor sitting position has been suggested as an etiologic factor. This study analysed, in primary schoolchildren, the influence of a triangular dynamic cushion that aims to help children maintain their physiological lumbar lordosis and to induce movement to reduce the static effect of the sitting position.
Methods: Thirty 8-year-old children took part in this study. A 3D analysis combined with electromyography was used to evaluate the biomechanics and the related muscle activation in two sitting positions (with and without a triangular cushion on a horizontal stool) during a 15-minute working task. In addition, the force of the feet on the ground was assessed with a force plate.
Findings: The cushion improved the trunk-thighs angle, lumbar lordosis, anterior pelvis tilt, and feet support on the ground (p<0.0001). In addition, sitting on the cushion appeared to be more dynamic (p<0.05) and induced a decrease of the lumbar paravertebral muscle activity (p<0.01).
Interpretation: Sitting on a dynamic triangular cushion tends to favour the "ideal" siting position usually described in the literature and to decrease the level of paravertebral muscle recruitment. Seeing that sitting position is a risk factor to develop low back pain, the cushion could be a solution to prevent it.
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http://dx.doi.org/10.1016/j.clinbiomech.2017.09.002 | DOI Listing |
J Hazard Mater
January 2025
College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China. Electronic address:
The cyclic triangular complex - silver (I) 4-nitro-3,5-bis(trifluoromethyl)pyrazolate (Agpz) with super π-acidity shows great potential in adsorptive desulfurization (ADS) as a novel adsorbent, however, it fails to work well in the continue flow adsorption study. In order to improve its dynamic adsorption performance, a composite has been prepared by mixing Agpz and multilayer graphene (MG) in methanol. Based on the results of characterization by FT-IR, XPS, SEM, and so on, the optimal mass ratio of Agpz:MG in the synthesis is 0.
View Article and Find Full Text PDFSoft Robot
January 2025
Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China.
Soft actuators hold great potential for applications in surgical operations, robotic manipulation, and prosthetic devices. However, they are limited by their structures, materials, and actuation methods, resulting in disadvantages in output force and dynamic response. This article introduces a soft pneumatic actuator capable of bending based on triangular prism origami.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Applied Chemistry, Aligarh Muslim University, Aligarh, 202002, India.
A porous and flexible Zn-MOF was synthesized under solvothermal conditions by using the ligand 2,5-furandicarboxylic acid (2,5-FDA). This flexible Zn-MOF demonstrates a temperature-triggered breathing effect. At low temperature (100 K), we obtained the high-symmetry MOF denoted as with a unit cell volume of 1958 Å, characterized by triangular narrow pore (np) channels.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454003, China.
Nickel (Ni) single-layer coatings were electrodeposited under varying pulse periods (T), duty cycles (θ), and average current densities (i) using four distinct pulse current waveforms: rectangular (Rec), triangular (Tri), ramp-up triangular (Rup), and ramp-down triangular (Rdn). This study demonstrated, through dynamic polarization curves and surface morphology analysis, that single-layer coatings showed relatively good corrosion resistance when deposited at shorter pulse periods, larger duty cycles, and higher average current densities. Moreover, compared with other pulse current waveforms, single-layer coatings electrodeposited at T = 10 ms, θ = 0.
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China.
In the case of waveguide-based devices, once they are fabricated, their optical properties are already determined and cannot be dynamically controlled, which limits their applications in practice. In this paper, an isosceles triangular-coupling structure which consists of an isosceles triangle coupled with a two-bus waveguide is proposed and researched numerically and theoretically. The coupled mode theory (CMT) is introduced to verify the correctness of the simulation results, which are based on the finite difference time domain (FDTD).
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