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Power Lifting

P Ibbott, N Ball, M Welvaert, K G Thompson
We investigated the variability of strength trained athletes' self-selected rest periods between sets of heavy squat training. Sixteen strength-trained male athletes (Mage  = 23, SD = 3 years) completed two squat training sessions 48 hours apart. Each training session consisted of five sets of 5RM squats, interspersed with self-selected interset rest periods. A Gymaware linear optical encoder collected kinetic data for each squat and temporal data for each interset rest period. The participants' subjective ratings of the experience were taken before (Readiness to Lift [RTL]) and after (Rating of Perceived Effort [RPE]) each set...
March 13, 2019: Perceptual and Motor Skills
Franck Di Rienzo, Fanny Barlaam, Sébastien Daligault, Claude Delpuech, Alice C Roy, Olivier Bertrand, Karim Jerbi, Christina Schmitz
During bimanual coordination, that is, manipulating with the dominant hand an object held by the postural hand, anticipatory postural adjustments are required to cancel the perturbations and ensure postural stabilization. Using magnetoencephalography (MEG), we investigated changes mediating the acquisition of anticipatory postural adjustments during a bimanual load-lifting task. Participants lifted a load with their right hand, hence triggering the fall of a second load fixed to their left (postural) forearm...
March 13, 2019: Human Brain Mapping
Mark Greenhalgh, James Matthew Landis, Joshua Brown, Hailee Kulich, Sarah Bass, Saleh Alqahtani, Nikitha Deepak, Garrett Grindle, Alicia M Koontz, Rory A Cooper
OBJECTIVE: Manual lifting can be burdensome for people who care for power wheelchair users. Though technologies used for dependent transfers are helpful, they have shortcomings of their own. This study compares the usability and task load demand of a novel robotic assisted transfer device to a clinical standard when performing dependent transfers. DESIGN: A cross-sectional study was conducted to assess caregivers (N=21) transferring a 56 kg mannequin with the Strong Arm and Hoyer Advance at three transfer locations...
March 8, 2019: American Journal of Physical Medicine & Rehabilitation
Donald P Meckley, Kendall Hulbert, Drew Stewart, Nick O'Brien, Nick Barringer, Jared H Hornsby
Muscular strength, power, and aerobic capacity are vital to Army Reserve Officer Training Corps (AROTC) Cadets as well as active-duty Soldiers, especially when lifting heavy objects, traveling long distances, or moving with maximum speed and agility. The purpose of this study was to examine the change (after a pre/post intervention) of 5 weeks of resistance strength training and aerobic capacity training on a Ranger Athlete Warrior (RAW) assessment. Twelve (males, n = 10; females, n = 2) college-aged AROTC Cadets volunteered for this study during their train-up for the annual Ranger Challenge Competition...
2019: Journal of Special Operations Medicine: a Peer Reviewed Journal for SOF Medical Professionals
Erika Zemková, Oliver Poór, Juraj Pecho
This study investigates the relationship between peak force and rate of force development (RFD) obtained from maximal voluntary isometric contraction (MVC) of the back muscles and the power produced during a loaded lifting task. A group of 27 resistance-trained and 41 recreationally physically active men performed a maximal isometric strength test of the back muscles and a deadlift to high pull while lifting progressively increasing weights. Peak RFD correlated significantly with the peak and mean power produced during a deadlift to high pull with lower weights (from 20 to 40 kg), with r values ranging from ...
January 2019: American Journal of Men's Health
Kristen L Kucera, Ashley L Schoenfisch, Jennifer McIlvaine, Lori Becherer, Tamara James, Yeu-Li Yeung, Susan Avent, Hester J Lipscomb
BACKGROUND: Despite wide availability of patient lift equipment in hospitals to promote worker and patient safety, nursing staff do not consistently use equipment. OBJECTIVE: To determine the influence of factors on the use or non-use of lift equipment during patient lifts/transfers. DESIGN: Prospective observational cohort study. SETTING: One university teaching hospital and two community hospitals in a large health system in southeastern United States...
December 31, 2018: International Journal of Nursing Studies
Christopher P Hedges, Reuben T Wilkinson, Jules B L Devaux, Anthony J R Hickey
Insect flight is a high intensity activity, but biomechanical and metabolic requirements may vary depending on life style and feeding mode. For example, bees generally feed on pollen and nectar, whereas wasps also actively hunt and scavenge heavy prey. These variations in metabolic demands may result in different capacities of metabolic pathways in flight muscle, and utilisation some of these pathways may come at a cost of increased free radical production. To examine how metabolic requirements and oxidative stress vary between species, we explored the variation in flight mechanics and metabolism of the honeybee (Apis mellifera), bumblebee (Bombus terrestris), and German wasp (Vespula germanica)...
January 21, 2019: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Peter Ibbott, N B Ball, Marijke Welvaert, Kevin G Thompson
PURPOSE: To assess pacing strategies using prescribed and self-selected inter-set rest periods and their influence on performance in strength trained athletes. METHODS: Sixteen strength-trained male athletes completed three randomised heavy-strength training sessions (five sets, five repetitions) with different inter-set rest periods. The inter-set rest periods were: 3 minute (3MIN ), 5 minute (5MIN ) and Self-Selected (SS). Mechanical (power, velocity, work and displacement), surface muscle activity (sEMG) and subjective (Rating of Perceived Exertion -RPE) and readiness to lift (RTL) data were recorded for each set...
January 24, 2019: International Journal of Sports Physiology and Performance
Majid S Koozehchian, Amin Daneshfar, Ebrahim Fallah, Hamid Agha-Alinejad, Mohammad Samadi, Mojtaba Kaviani, Maryam Kaveh B, Y Peter Jung, Mozhgan Hassanzadeh Sablouei, Najmeh Moradi, Conrad P Earnest, T Jeff Chandler, Richard B Kreider
PURPOSE: Studies of L-carnitine in healthy athletic populations have yielded equivocal results. Further scientific-based knowledge is needed to clarify the ability of L-carnitine to improve exercise capacity and expedite the recovery process by reducing oxidative stress. This study aimed to examine the 9-week effects of L-carnitine supplementation on exercise performance, anaerobic capacity, and exercise-induced oxidative stress markers in resistance-trained males. METHODS: In a double-blind, randomized, and placebo-controlled treatment, 23 men (age, 25±2y; weight, 81...
December 31, 2018: Journal of Exercise Nutrition & Biochemistry
Kang Lai, Hongxing Li, Yuan-Kai Xu, Wei-Bing Zhang, Jiayu Dai
Type-II van der Waals (vdW) heterostructures are considered as a class of competitive candidates of high-efficiency photovoltaic materials, due to their spontaneous electron-hole separation. However, most of the vdW heterostructures possess an indirect gap and a large band offset, which would lead to low photon-to-electron conversion efficiency. Taking an SbI3/BiI3 vdW heterostructure as an illustrative example, we propose interlayer compression and vertical electric field application as two effective strategies to modulate the electronic and photovoltaic properties of type-II vdW heterostructures...
January 18, 2019: Physical Chemistry Chemical Physics: PCCP
Kosuke Suzuki, Masato Yoshino
Wing planform is one of important factors for lift and thrust generation and enhancement in flapping flight. In our previous study using a simple numerical model of a butterfly, it was found that the wing planform of an actual butterfly (Janatella leucodesma) is more efficient than any of the rectangular or trapezoidal wing planforms. In the present study, we make a hypothesis that the efficient aerodynamic performance of the butterfly's wing can be reproduced by the following four geometrical parameters of wing planform: aspect ratio, taper ratio, position of the rotational axis for the geometric angle of attack, and sweepback angle...
January 11, 2019: Bioinspiration & Biomimetics
Ellis J Brotherton, Sarah E Moseley, Carl Langan-Evans, Samuel A Pullinger, Colin M Robertson, Jatin G Burniston, Ben J Edwards
We have investigated the effects that sleep restriction (3-h sleep during two consecutive nights) have on an evening (17:00 h) submaximal weightlifting session; and whether this performance improves following a 1-h post-lunch powernap. Fifteen resistance-trained males participated in this study. Before the experimental protocol commenced, 1RM bench press and inclined leg press and normative habitual sleep were recorded. Participants were familiarised with the testing protocol, then completed three experimental conditions with two nights of prescribed sleep: (i) Normal (N): retire at 23:00 h and wake at 06:30 h, (ii) partial sleep-deprivation (SD): retire at 03:30 h and wake at 06:30 h and (iii) partial sleep-deprivation with nap (SDN ): retire at 03:30 h and wake at 06:30 h with a 1-h nap at 13:00 h...
March 2019: Chronobiology International
Roman Szewczyk
This paper presents a model of the magnetostrictive hysteresis loop with local maximum. The model is based on the differential equations describing magnetostriction due to the domain wall movement as well as domain magnetization rotation. The transition between these mechanisms of magnetization is quantified by the Maxwell⁻Boltzmann distribution. Moreover, the lift-off phenomenon in the magnetostrictive hysteresis loop is considered. The proposed model was validated on the results of measurements of magnetostrictive hysteresis loops of Mn0...
December 30, 2018: Materials
Christopher G Ballmann, Marquis J McCullum, Rebecca R Rogers, Mallory M Marshall, Tyler D Williams
Ballmann, CG, McCullum, MJ, Rogers, RR, Marshall, MM , and Williams, TD. Effects of preferred vs. nonpreferred music on resistance exercise performance. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to examine the effects of listening to preferred vs. nonpreferred music on resistance exercise performance. Twelve resistance-trained college-aged males (age = 20.5 ± 1.24 years, height = 183.9 ± 6.8 cm, and body mass = 97.0 ± 18.2 kg) were recruited for this study. In a within-groups counterbalanced study design, participants either listened to preferred or nonpreferred music during a bench press exercise test...
December 7, 2018: Journal of Strength and Conditioning Research
S M Mizanoor Rahman, Ryojun Ikeura
In the first step, a 1-DOF power-assist robotic system (PARS) is developed for lifting lightweight objects. Dynamics for human-robot co-manipulation of objects is derived that considers human cognition (weight perception). Then, admittance control with position feedback and velocity controller is derived using weight perception-based dynamics. Human subjects lift an object with the PARS, and HRI (human-robot interaction) and system characteristics are analyzed. A comprehensive scheme is developed to evaluate the HRI and performance...
2018: Robotics and Biomimetics
Á Vicente-Retortillo, G M Martínez, N Renno, C E Newman, I Ordonez-Etxeberria, M T Lemmon, M I Richardson, R Hueso, A Sánchez-Lavega
In situ measurements by the Curiosity rover provide a unique opportunity for studying the effects of dust on assets placed at the surface of Mars. Here we use in situ measurements of solar UV radiation to quantify the seasonal and interannual variability of dust accumulation on the sensor on the rover deck. We show that the amount of dust accumulated on the sensor follows a seasonal cycle, with net dust removal during the perihelion season until Ls ~ 300°, and net dust deposition until the end of the aphelion season (Ls ~ 300°-180°)...
December 4, 2018: Scientific Reports
E S Strotmeyer, M E Winger, J A Cauley, R M Boudreau, D Cusick, R F Collins, D Chalhoub, B Buehring, E Orwoll, T B Harris, P Caserotti
OBJECTIVE: To determine normative values for weight-bearing, countermovement leg extension ("jump") tests in the oldest men and characteristics of those not completing vs. completing tests. DESIGN: 2014-16 cross-sectional exam. SETTING: Six U.S. sites from the Osteoporotic Fractures in Men (MrOS) Study. PARTICIPANTS: Community-dwelling men (N=1,841) aged 84.5±4.2 (range: 77-101) years. INTERVENTIONS: N/A...
2018: Journal of Nutrition, Health & Aging
Deborah McGott, Michael D Kempe, Stephen Glynn, Nick Bosco, Teresa M Barnes, Nancy M Haegel, Colin A Wolden, Matthew O Reese
Controlled delamination of thin-film photovoltaics (PV) post-growth can reveal interfaces that are critical to device performance, yet are poorly understood due to their inaccessibility within the device stack. In this work, we demonstrate a technique to lift off thin-film solar cells from their glass substrates in a clean, reproducible manner by first laminating a polymeric backsheet to the device, then thermally shocking the system at low temperatures (T ≤ -30˚C). To enable clean delamination of diverse thin-film architectures, a theoretical framework is developed and key process control parameters are identified...
November 29, 2018: ACS Applied Materials & Interfaces
Peter Windes, Xiaozhou Fan, Matt Bender, Danesh K Tafti, Rolf Müller
The aerodynamic mechanisms of bat flight have been studied using a numerical approach. Kinematic data acquired using a high resolution motion capture system was employed to simulate the unsteady air flow around a bat's wings. A flapping bat wing contains many degrees of freedom, which make 3D motion tracking challenging. In order to overcome this challenge, an optical motion capture system of 21 cameras was used to reduce wing self-occlusion. Over the course of a meter-long flight, 108 discrete marker points on the bat's wings (Pratt's roundleaf bat, Hipposideros pratti) were tracked...
2018: PloS One
Idoia Castellanos-Rubio, Rahul Munshi, Yueling Qin, David B Eason, Iñaki Orue, Maite Insausti, Arnd Pralle
The two major limitations for nanoparticle based magnetic hyperthermia in theranostics are the delivery of a sufficient number of magnetic nanoparticles (MNPs) with high heating power to specific target cells and the residence time of the MNPs at the target location. Ferromagnetic or Ferrimagnetic single domain nanoparticles (F-MNPs), with a permanent magnetic dipole, produce larger magnetic and thermal responses than superparamagnetic nanoparticles (SP-MNPs) but also agglomerate more. MNP agglomeration degrades their heating potential due to dipolar interaction effects and interferes with specific targeting...
November 29, 2018: Nanoscale
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