Time-varying motor control strategy for proximal-to-distal sequential energy distribution: Insights from baseball pitching

Journal of Experimental Biology ◽

10.1242/jeb.227207 ◽

2021 ◽

Author(s):

Kozo Naito

Keyword(s):

Energy Transfer ◽

Motor Control ◽

Energy Distribution ◽

Mechanical Energy ◽

Movement Control ◽

Mechanical Efficiency ◽

Primary Energy ◽

Time Varying ◽

Collegiate Baseball ◽

Work Production

The importance of a proximal-to-distal (P-D) sequential motion in baseball pitching is generally accepted; however, the mechanisms behind this sequential motion and motor control theories that explain which factor transfers mechanical energy between the trunk and arm segments are not completely understood. This study aimed to identify the energy distribution mechanisms among the segments and determine the effect of the P-D sequence on the mechanical efficiency of the throwing movement, focusing on the time-varying motor control. The throwing motions of 16 male collegiate baseball pitchers were measured by a motion capture system. An induced power analysis was used to decompose the system mechanical energy into its muscular and interactive torque-dependent components. The results showed that the P-D sequential energy flow during the movement was mainly attributed to three different joint controls of the energy-generation and muscular torque- and centrifugal force-induced energy-transfer. The trunk muscular torques provided the primary energy sources of the system mechanical energy, and the shoulder and elbow joints played the roles of the energy-transfer effect. The mechanical energy expenditure on the throwing hand and ball accounted for 72.7% of the total muscle work generated by the trunk and arm joints (329.2 J). In conclusion, the P-D sequence of the throwing motion is an effective way to utilize the proximal joints as the energy source and reduce muscular work production of the distal joints. This movement control assists in efficient throwing, and is consistent with the theory of the leading joint hypothesis.

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AORTOVENTRICULAR MECHANICAL MATCHING: SIMULATION OF NORMAL AND PATHOLOGICAL CONDITIONS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519408002498 ◽

2008 ◽

Vol 08 (01) ◽

pp. 109-120 ◽

Cited By ~ 7

Author(s):

ROMANO ZANNOLI ◽

IVAN CORAZZA ◽

ANGELO BRANZI ◽

PIER LUCA ROSSI

Keyword(s):

Energy Transfer ◽

Mechanical Energy ◽

Systolic Pressure ◽

Ventricular Elastance ◽

Pathological Conditions ◽

Work Production ◽

Cardiovascular Pathologies ◽

Volume Relation ◽

Set Up

A mechanical mock of the cardiovascular system was used to simulate different conditions of ventricular-arterial mechanical matching. Four ventricles and four aortas with different elastances were set up, and all possible connection combinations tested by sampling ventricular and aortic pressures and flows. The mechanical energy produced by the simulated ventricles and the amount transferred to the aorta in the different connection conditions were calculated. The results demonstrate a clear dependence between the mechanical work production of the ventricles and the ventricular elastance (slope of the end-systolic pressure–volume relation) (from 20.42 ± 0.02 mJ/beat to 12.10 ± 0.02 mJ/beat), and an efficiency of energy transfer to the aorta strongly dependent on ventricular-aortic mechanical matching (from 56% to 20.7%). These results show that, even in optimal simulated conditions, only 56% of the energy produced is transferred to the load; and highlight the important role of mechanical aspects in conditions of very limited cardiovascular performance (i.e. final stages of heart failure), where energy transfer efficiency may be as low as 20.7%. This evidence emphasizes that the mechanical aspects must also be entertained in the evolution of complex cardiovascular pathologies, evaluating the possibility of combining mechanical and pharmaceutical interventions.

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Energy distribution over the cross section of the track of charged particles having the same linear energy transfer

Soviet Atomic Energy ◽

10.1007/bf02116036 ◽

1973 ◽

Vol 34 (4) ◽

pp. 372-373

Author(s):

I. K. Kalugina ◽

I. B. Keirim-Markus ◽

A. K. Savinskii ◽

I. V. Filyushkin

Keyword(s):

Energy Transfer ◽

Energy Distribution ◽

Cross Section ◽

Linear Energy Transfer ◽

Charged Particles ◽

The Cross

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On the primary energy distribution and the EBL limits from TeV Blazars

10.1063/1.3076719 ◽

2008 ◽

Author(s):

A. Meli ◽

T. Kneiske ◽

J. K. Becker ◽

Felix A. Aharonian ◽

Werner Hofmann ◽

...

Keyword(s):

Energy Distribution ◽

Primary Energy

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Interphasial energy transfer and particle dissipation in particle-laden wall turbulence

Journal of Fluid Mechanics ◽

10.1017/jfm.2012.492 ◽

2013 ◽

Vol 715 ◽

pp. 32-59 ◽

Cited By ~ 50

Author(s):

Lihao Zhao ◽

Helge I. Andersson ◽

Jurriaan J. J. Gillissen

Keyword(s):

Energy Transfer ◽

Kinetic Energy ◽

Stokes Equations ◽

Mechanical Energy ◽

Wall Turbulence ◽

Spherical Particles ◽

Velocity Versus ◽

Wall Region ◽

Carrier Fluid ◽

Stokes Force

AbstractTransfer of mechanical energy between solid spherical particles and a Newtonian carrier fluid has been explored in two-way coupled direct numerical simulations of turbulent channel flow. The inertial particles have been treated as individual point particles in a Lagrangian framework and their feedback on the fluid phase has been incorporated in the Navier–Stokes equations. At sufficiently large particle response times the Reynolds shear stress and the turbulence intensities in the spanwise and wall-normal directions were attenuated whereas the velocity fluctuations were augmented in the streamwise direction. The physical mechanisms involved in the particle–fluid interactions were analysed in detail, and it was observed that the fluid transferred energy to the particles in the core region of the channel whereas the fluid received kinetic energy from the particles in the wall region. A local imbalance in the work performed by the particles on the fluid and the work exerted by the fluid on the particles was observed. This imbalance gave rise to a particle-induced energy dissipation which represents a loss of mechanical energy from the fluid–particle suspension. An independent examination of the work associated with the different directional components of the Stokes force revealed that the dominating energy transfer was associated with the streamwise component. Both the mean and fluctuating parts of the Stokes force promoted streamwise fluctuations in the near-wall region. The kinetic energy associated with the cross-sectional velocity components was damped due to work done by the particles, and the energy was dissipated rather than recovered as particle kinetic energy. Componentwise scatter plots of the instantaneous velocity versus the instantaneous slip-velocity provided further insight into the energy transfer mechanisms, and the observed modulations of the flow field could thereby be explained.

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Mechanical-to-Mechanical Energy Transfer

Essentials of Piezoelectric Energy Harvesting ◽

10.1142/9789811234644_0004 ◽

2021 ◽

pp. 109-138

Keyword(s):

Energy Transfer ◽

Mechanical Energy

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Adaptive timing, attention, and movement control

Behavioral and Brain Sciences ◽

10.1017/s0140525x97281598 ◽

1997 ◽

Vol 20 (4) ◽

pp. 619-619 ◽

Cited By ~ 1

Author(s):

Stephen Grossberg

Keyword(s):

Motor Control ◽

Movement Control ◽

The Difference ◽

Adaptive Timing

Examples of how LTP and LTD can control adaptively-timed learning that modulates attention and motor control are given. It is also suggested that LTP/LTD can play a role in storing memories. The distinction between match-based and mismatch-based learning may help to clarify the difference.

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Cerulenin-Induced Modifications in the Fatty Acid Composition Affect Excitation Energy Transfer in Thylakoids of Petunia hybrida Leaves

Zeitschrift für Naturforschung C ◽

10.1515/znc-1988-5-618 ◽

1988 ◽

Vol 43 (5-6) ◽

pp. 431-437 ◽

Cited By ~ 1

Author(s):

Josef A. Graf ◽

Karin Witzan ◽

Reto J. Strasser

Keyword(s):

Fatty Acid Composition ◽

Energy Transfer ◽

Fatty Acid ◽

Photosystem Ii ◽

Energy Distribution ◽

Excitation Energy ◽

Acid Composition ◽

Petunia Hybrida ◽

Excitation Energy Transfer ◽

Acyl Lipids

Cerulenin-induced modifications in the fatty acid composition have been used to investigate the influence of acyl lipids on excitation energy distribution in thylakoid membranes of Petunia hybrida by means of 77 K fluorescence spectroscopy. Although cerulenin has no effect on relative contents of chlorophyll and acyl lipids, changes in the fatty acid composition of all thylakoid acyl lipids have been observed. The main cerulenin effect seems to be an increase in linoleic acid at the expense of saturated and monounsaturated C16- and C18-fatty acids resulting most likely in an increase in acyl lipid species containing both linoleic and linolenic acid. Low temperature (77 K ) fluorescence kinetics reveal a remarkable decrease in the ratio of the variable divided by the maximal fluorescence of photosystem II (F2(v)/F2(M)), taken as indicator for cerulenin-induced changes in this photosystem. Calculations of the excitation energy distribution terms based on a grouped bipartite model of photosynthesis suggest that a decrease in this ratio is caused by changes in energy transfer probabilities responsible for both, photochemical trapping of photosystem II and energetic cooperativity (grouping) between different photosystem II-light harvesting complex-units. Moreover, changes in the conformation responsible for spillover energy transfer are most likely to occur. Correlations between cerulenin-induced modifications of fatty acid composition and energy distribution support the assumption that excitation energy transfer depends on the structural state of the lipid matrix.

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Depressed Cardiac Mechanical Energetic Efficiency: A Contributor to Cardiovascular Risk in Common Metabolic Diseases—From Mechanisms to Clinical Applications

Journal of Clinical Medicine ◽

10.3390/jcm9092681 ◽

2020 ◽

Vol 9 (9) ◽

pp. 2681

Author(s):

Albert Juszczyk ◽

Karolina Jankowska ◽

Barbara Zawiślak ◽

Andrzej Surdacki ◽

Bernadeta Chyrchel

Keyword(s):

Heart Failure ◽

Metabolic Syndrome ◽

Energy Transfer ◽

Metabolic Diseases ◽

Mechanical Energy ◽

Second Step ◽

Energetic Efficiency ◽

Preserved Ejection Fraction ◽

The Third ◽

Total Mechanical Energy

Cardiac mechanical energetic efficiency is the ratio of external work (EW) to the total energy consumption. EW performed by the left ventricle (LV) during a single beat is represented by LV stroke work and may be calculated from the pressure–volume loop area (PVLA), while energy consumption corresponds to myocardial oxygen consumption (MVO2) expressed on a per-beat basis. Classical early human studies estimated total mechanical LV efficiency at 20–30%, whereas the remaining energy is dissipated as heat. Total mechanical efficiency is a joint effect of the efficiency of energy transfer at three sequential stages. The first step, from MVO2 to adenosine triphosphate (ATP), reflects the yield of oxidative phosphorylation (i.e., phosphate-to-oxygen ratio). The second step, from ATP split to pressure–volume area, represents the proportion of the energy liberated during ATP hydrolysis which is converted to total mechanical energy. Total mechanical energy generated per beat—represented by pressure–volume area—consists of EW (corresponding to PVLA) and potential energy, which is needed to develop tension during isovolumic contraction. The efficiency of the third step of energy transfer, i.e., from pressure–volume area to EW, decreases with depressed LV contractility, increased afterload, more concentric LV geometry with diastolic dysfunction and lower LV preload reserve. As practical assessment of LV efficiency poses methodological problems, De Simone et al. proposed a simple surrogate measure of myocardial efficiency, i.e., mechano-energetic efficiency index (MEEi) calculated from LV stroke volume, heart rate and LV mass. In two independent cohorts, including a large group of hypertensive subjects and a population-based cohort (both free of prevalent cardiovascular disease and with preserved ejection fraction), low MEEi independently predicted composite adverse cardiovascular events and incident heart failure. It was hypothesized that the prognostic ability of low MEEi can result from its association with both metabolic and hemodynamic alterations, i.e., metabolic syndrome components, the degree of insulin resistance, concentric LV geometry, LV diastolic and discrete systolic dysfunction. On the one part, an increased reliance of cardiomyocytes on the oxidation of free fatty acids, typical for insulin-resistant states, is associated with both a lower yield of ATP per oxygen molecule and lesser availability of ATP for contraction, which might decrease energetic efficiency of the first and second step of energy transfer from MVO2 to EW. On the other part, concentric LV remodeling and LV dysfunction despite preserved ejection fraction can impair the efficiency of the third energy transfer step. In conclusion, the association of low MEEi with adverse cardiovascular outcome might be related to a multi-step impairment of energy transfer from MVO2 to EW in various clinical settings, including metabolic syndrome, diabetes, hypertension and heart failure. Irrespective of theoretical considerations, MEEi appears an attractive simple tool which couldt improve risk stratification in hypertensive and diabetic patients for primary prevention purposes. Further clinical studies are warranted to estimate the predictive ability of MEEi and its post-treatment changes, especially in patients on novel antidiabetic drugs and subjects with common metabolic diseases and concomitant chronic coronary syndromes, in whom the potential relevance of MEE can be potentiated by myocardial ischemia.

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