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https://www.readbyqxmd.com/read/28814048/a-mechanism-for-elbow-exoskeleton-for-customised-training
#1
Soumya K Manna, Venketesh N Dubey
It is well proven that repetitive extensive training consisting of active and passive therapy is effective for patients suffering from neuromuscular deficits. The level of difficulty in rehabilitation should be increased with time to improve the neurological muscle functions. A portable elbow exoskeleton has been designed that will meet these requirements and potentially offers superior outcomes than human-assisted training. The proposed exoskeleton can provide both active and passive rehabilitation in a single structure without changing its configuration...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814019/stiffness-control-of-a-nylon-twisted-coiled-actuator-for-use-in-mechatronic-rehabilitation-devices
#2
Brandon P R Edmonds, Ana Luisa Trejos
Mechatronic rehabilitation devices, especially wearables, have been researched extensively and proven to be promising additions to physical therapy, but most designs utilize traditional actuators providing unnatural, robot-like movements. Therefore, many researchers have focused on the development of actuators that mimic biological properties to provide patients with improved results, safety, and comfort. Recently, a twisted-coiled actuator (TCA) made from nylon thread has been found to possess many of these important properties when heated, such as variable stiffness, flexibility, and high power density...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813886/exploratory-design-of-a-compliant-mechanism-for-a-dynamic-hand-orthosis-lessons-learned
#3
Ronald A Bos, Dick H Plettenburg, Just L Herder
This study does not describe a success-story. Instead, it describes an exploratory process and the lessons learned while designing a compliant mechanism for a dynamic hand orthosis. Tools from engineering optimization and rapid prototyping techniques were used, with the goal to design a mechanism to compensate for hypertonic or contracted finger muscles. Results show that the mechanism did not reach its design constraints, mostly because it could not provide for the necessary stiffness and compliance at the same time...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813876/design-control-and-validation-of-the-variable-stiffness-exoskeleton-flexo
#4
Sariah Mghames, Marco Laghi, Cosimo Della Santina, Manolo Garabini, Manuel Catalano, Giorgio Grioli, Antonio Bicchi
In this paper we present the design of a one degree of freedom assistive platform to augment the strength of upper limbs. The core element is a variable stiffness actuator, closely reproducing the behavior of a pair of antagonistic muscles. The novelty introduced by this device is the analogy of its control parameters with those of the human muscle system, the threshold lengths. The analogy can be obtained from a proper tuning of the mechanical system parameters. Based on this, the idea is to control inputs by directly mapping the estimation of the muscle activations, e...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813867/therapeutic-effects-of-anti-gravity-treadmill-alterg-training-on-reflex-hyper-excitability-corticospinal-tract-activities-and-muscle-stiffness-in-children-with-cerebral-palsy
#5
Sh Parvin, A Taghiloo, A Irani, M Mehdi Mirbagheri
We aimed to study therapeutic effects of antigravity treadmill (AlterG) training on reflex hyper-excitability, muscle stiffness, and corticospinal tract (CST) function in children with spastic hemiplegic cerebral palsy (CP). Three children received AlterG training 3 days per week for 8 weeks as experimental group. Each session lasted 45 minutes. One child as control group received typical occupational therapy for the same amount of time. We evaluated hyper-excitability of lower limb muscles by H-reflex response...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813852/event-based-control-for-sit-to-stand-transition-using-a-wearable-exoskeleton
#6
Vijaykumar Rajasekaran, Manuel Vinagre, Joan Aranda
Sit-to-stand transition is an essential step in a lower limb rehabilitation therapy, mainly for assisting the patient to transit from wheel chair to the next level of therapy. A mixed stiffness-damping control adaptation is proposed for this task which will help in reaching the final position with a constant velocity. A combination of control model is proposed to ensure the initiation and the final stage of the transition, such as to ensure stability and to maintain the equilibrium. The combined control model helps in reaching the goal position with equal participation from the user...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28806708/predictive-simulation-of-diabetic-gait-individual-contribution-of-ankle-stiffness-and-muscle-weakening
#7
Gilmar F Santos, Aline A Gomes, Isabel C N Sacco, Marko Ackermann
Diabetic neuropathic individuals present massive muscle strength reduction at the ankle plantar- and dorsiflexors and increased joint stiffness. Our aim is to investigate the adaptation strategies to these musculoskeletal alterations during walking by means of predictive simulations. We used a seven segment planar musculoskeletal model actuated by eight Hill-type muscles in each leg. The effect of all passive tissue in muscles and other joint structures was modeled by net passive joint moment curves. The predictive simulations were generated by solving an optimal control problem that minimized a cost function, including effort and tracking terms, using direct collocation and a commercial optimal control package...
August 1, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28806290/-clinical-and-quantitative-isokinetic-comparison-of-abdominal-morbidity-and-dynamics-following-diep-versus-muscle-sparing-free-tram-flap-breast-reconstruction
#8
Hirokazu Uda, Hideaki Kamochi, Syunji Sarukawa, Ataru Sunaga, Yasusih Sugawara, Kotaro Yoshimura
BACKGROUND: The deep inferior epigastric perforator (DIEP) flap, which is a modification of the muscle-sparing free transverse rectus abdominis musculocutaneous (msTRAM) flap, is being more frequently used in an effort to reduce postoperative abdominal morbidity. However, there is no consensus as to which of these flaps is superior. We aimed to compare quantitative measurements of abdominal function obtained with an isokinetic dynamometer after DIEP and msTRAM flap elevation. METHODS: Patients who underwent unilateral single-pedicled DIEP (n = 42) or msTRAM flap (n = 36) breast reconstruction performed by a single surgeon were included in this study...
August 3, 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28802220/comparison-of-lower-limb-muscle-strength-between-diabetic-neuropathic-and-healthy-subjects-using-opensim
#9
Alessandra Scarton, Ilse Jonkers, Annamaria Guiotto, Fabiola Spolaor, Gabriella Guarneri, Angelo Avogaro, Claudio Cobelli, Zimi Sawacha
Diabetes neuropathy and vasculopathy are the two major complications of diabetes mellitus, leading to diabetic foot disease, of which the worst consequences are plantar ulcers and amputations. Motor impairments like joint stiffness and loss of balance are distinctive effects of diabetes and they have been extensively explored. However, while altered muscle function has been also assessed through experimentally measured surface electromyography, little is known about muscle forces. The objective of this study was to estimate muscle forces in subjects with diabetes and to use these data to identify differences with respect to a population of healthy subjects matched for age and BMI...
July 31, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28801956/evidence-of-er-stress-and-upr-activation-in-patients-with-brody-disease-and-brody-syndrome
#10
V Guglielmi, N C Voermans, A Oosterhof, D Nowis, B G van Engelen, G Tomelleri, G Vattemi
Brody disease (BD, OMIM #601003) is an inherited skeletal muscle disease clinically characterized by exercise-induced impairment of muscle relaxation and stiffness due to the delay in the Ca(2+) re-uptake in the sarcoplasmic reticulum (SR)[1, 2]. The delayed muscle relaxation mainly affects legs, harms, hands and eyelids and usually improves after a few minutes rest [1-3]. Patients frequently report myalgia, painless or mildly painful cramps whereas recurrent rhabdomyolysis have been described in a few cases [2, 3]...
August 12, 2017: Neuropathology and Applied Neurobiology
https://www.readbyqxmd.com/read/28801950/can-chronic-stretching-change-the-muscle-tendon-mechanical-properties-a-review
#11
REVIEW
Sandro R Freitas, Bruno Mendes, Guillaume Le Sant, Ricardo J Andrade, Antoine Nordez, Zoran Milanovic
PURPOSE: It is recognized that stretching is an effective method to chronically increase the joint range of motion. However, the effects of stretching training on the muscle-tendon structural properties remain unclear. This systematic review with meta-analysis aimed to determine whether chronic stretching alter the muscle-tendon structural properties. METHODS: Published papers regarding longitudinal stretching (static, dynamic and/or PNF) intervention (either randomized or not) in humans of any age and health status, with more than 2 weeks in duration and at least 2 sessions per week, were searched in PubMed, PEDro, ScienceDirect and ResearchGate databases...
August 12, 2017: Scandinavian Journal of Medicine & Science in Sports
https://www.readbyqxmd.com/read/28801518/effects-of-plyometric-and-isometric-training-on-muscle-and-tendon-stiffness-in%C3%A2-vivo
#12
Keitaro Kubo, Tomonobu Ishigaki, Toshihiro Ikebukuro
The purpose of this study was to compare the effects of plyometric and isometric training on tendon properties during ramp and ballistic contractions and muscle stiffness under passive and active conditions. Eleven subjects completed 12 weeks (3 days/week) of a unilateral training program for the plantar flexors. They performed plyometric training on one side (PLY) and isometric training on the other side (ISO). Active muscle stiffness in the medial gastrocnemius muscle was calculated according to changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions...
August 2017: Physiological Reports
https://www.readbyqxmd.com/read/28799161/performance-factors-in-a-mountain-ultramarathon
#13
Pascal Balducci, Michel Clémençon, Robin Trama, Yoann Blache, Christophe Hautier
This study aimed to determine mountain ultra-marathon (MUM) performance factors in a large group of endurance mountain runners. Maximal aerobic speed (MAS) was assessed one week prior to the MUM. The level and graded (10%) energy cost of running, stiffness, knee extensors force (KEf), and jump height on a counter movement jump (CMJ) were measured in 24 male ultra runners before (pre) and immediately after (post) the Interlacs Trail (75 km and 3 930/3 700 m d+/d-). Performance time was correlated with MAS (r=- 0...
August 10, 2017: International Journal of Sports Medicine
https://www.readbyqxmd.com/read/28798857/the-role-of-shear-stress-and-altered-tissue-properties-on-endothelial-to-mesenchymal-transformation-and-tumor-endothelial-cell-interaction
#14
Sara G Mina, Peter Huang, Bruce T Murray, Gretchen J Mahler
Tumor development is influenced by stromal cells in aspects including invasion, growth, angiogenesis, and metastasis. Activated fibroblasts are one group of stromal cells involved in cancer metastasis, and one source of activated fibroblasts is endothelial to mesenchymal transformation (EndMT). EndMT begins when the endothelial cells delaminate from the cell monolayer, lose cell-cell contacts, lose endothelial markers such as vascular endothelial-cadherin (VE-cadherin), gain mesenchymal markers like alpha-smooth muscle actin (α-SMA), and acquire mesenchymal cell-like properties...
July 2017: Biomicrofluidics
https://www.readbyqxmd.com/read/28797595/effects-of-motion-segment-simulation-and-joint-positioning-on-spinal-loads-in-trunk-musculoskeletal-models
#15
F Ghezelbash, A H Eskandari, A Shirazi-Adl, N Arjmand, Z El-Ouaaid, A Plamondon
Musculoskeletal models represent spinal motion segments by spherical joints/beams with linear/nonlinear properties placed at various locations. We investigated the fidelity of these simplified models (i.e., spherical joints with/without rotational springs and beams considering nonlinear/linear properties) in predicting kinematics of the ligamentous spine in comparison with a detailed finite element (FE) model while considering various anterior-posterior joint placements. Using the simplified models with different joint offsets in a subject-specific musculoskeletal model, we computed local spinal forces during forward flexion and compared results with intradiscal pressure measurements...
July 25, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28791501/skeletal-muscle-mass-to-visceral-fat-area-ratio-is-an-important-determinant-affecting-hepatic-conditions-of-non-alcoholic-fatty-liver-disease
#16
Takashi Shida, Kentaro Akiyama, Sechang Oh, Akemi Sawai, Tomonori Isobe, Yoshikazu Okamoto, Kazunori Ishige, Yuji Mizokami, Kenji Yamagata, Kojiro Onizawa, Hironori Tanaka, Hiroko Iijima, Junichi Shoda
BACKGROUND: Not only obesity but also sarcopenia is associated with NAFLD. The influence of altered body composition on the pathophysiology of NAFLD has not been fully elucidated. The aim of this study is to determine whether skeletal muscle mass to visceral fat area ratio (SV ratio) affects NAFLD pathophysiology. METHODS: A total of 472 subjects were enrolled. The association between SV ratio and NAFLD pathophysiological factors was assessed in a cross-sectional nature by stratification analysis...
August 8, 2017: Journal of Gastroenterology
https://www.readbyqxmd.com/read/28783377/extracellular-mitochondrial-dna-is-generated-by-fibroblasts-and-predicts-death-in-idiopathic-pulmonary-fibrosis
#17
Changwan Ryu, Huanxing Sun, Mridu Gulati, Jose D Herazo-Maya, Yonglin Chen, Awo Osafo-Addo, Caitlin Brandsdorfer, Julia Winkler, Christina Blaul, Jaden Faunce, Hongyi Pan, Tony Woolard, Argyrios Tzouvelekis, Danielle E Antin-Ozerkis, Jonathan T Puchalski, Martin Slade, Anjelica L Gonzalez, Daniel F Bogenhagen, Varvara Kirillov, Carol Feghali-Bostwick, Kevin Gibson, Kathleen Lindell, Raimund I Herzog, Charles S Dela Cruz, Wajahat Mehal, Naftali Kaminski, Erica Herzog, Glenda Trujillo
RATIONALE: Idiopathic pulmonary fibrosis (IPF) involves the accumulation of alpha smooth muscle actin (αSMA) expressing myofibroblasts arising from interactions with soluble mediators such as transforming growth factor beta-1 (TGFβ1), and mechanical influences such as local tissue stiffness. While IPF fibroblasts are enriched for aerobic glycolysis and innate immune receptor activation, innate immune ligands related to mitochondrial injury, such as extracellular mitochondrial DNA (mtDNA) have not been identified in IPF...
August 7, 2017: American Journal of Respiratory and Critical Care Medicine
https://www.readbyqxmd.com/read/28780647/cardiovascular-responses-to-skeletal-muscle-stretching-stretching-the-truth-or-a-new-exercise-paradigm-for-cardiovascular-medicine
#18
REVIEW
Nicholas T Kruse, Barry W Scheuermann
Stretching is commonly prescribed with the intended purpose of increasing range of motion, enhancing muscular coordination, and preventing prolonged immobilization induced by aging or a sedentary lifestyle. Emerging evidence suggests that acute or long-term stretching exercise may modulate a variety of cardiovascular responses. Specifically, at the onset of stretch, the mechanical deformation of the vascular bed coupled with stimulation of group III muscle afferent fibers initiates a cascade of events resulting in both peripheral vasodilation and a heart rate-driven increase in cardiac output, blood pressure, and muscle blood flow...
August 5, 2017: Sports Medicine
https://www.readbyqxmd.com/read/28775097/platelet-derived-growth-factor-receptor-alpha-pdgfr%C3%AE-and-ras-related-c3-botulinum-toxin-substrate-1-rac1-regulate-mechano-responsiveness-of-lung-fibroblasts
#19
Stephen E McGowan, Diann M McCoy
Platelet-derived growth factor (PDGF)-A, which only signals through PDGF-receptor-alpha (PDGFRα) is required for secondary alveolar septal formation. Although PDGFRα distinguishes mesenchymal progenitor cells during the saccular stage, PDGFRα-expressing alveolar cells persist through adulthood. PDGF-A sustains proliferation, limits apoptosis, and maintains alpha-smooth muscle actin (αSMA) containing alveolar cells, which congregate at the alveolar entry ring at postnatal day (P)12. PDGFRα-expressing, αSMA-containing, alveolar cells re-distribute in the elongating septum, suggesting that they migrate to the alveolar entry rings where mechanical tension is higher...
August 3, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
https://www.readbyqxmd.com/read/28765372/microfluidic-perfusion-shows-intersarcomere-dynamics-within-single-skeletal-muscle-myofibrils
#20
Felipe de Souza Leite, Fabio C Minozzo, David Altman, Dilson E Rassier
The sarcomere is the smallest functional unit of myofibrils in striated muscles. Sarcomeres are connected in series through a network of elastic and structural proteins. During myofibril activation, sarcomeres develop forces that are regulated through complex dynamics among their structures. The mechanisms that regulate intersarcomere dynamics are unclear, which limits our understanding of fundamental muscle features. Such dynamics are associated with the loss in forces caused by mechanical instability encountered in muscle diseases and cardiomyopathy and may underlie potential target treatments for such conditions...
August 15, 2017: Proceedings of the National Academy of Sciences of the United States of America
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