scholarly journals Physiology of Distinct Modes of Muscular Contraction

2018 ◽  
Vol 1 (3) ◽  
pp. 1-8
Author(s):  
Nasim Habibzadeh
Keyword(s):  
Muscle Contraction ◽  
Low Cost ◽  
Muscular Contraction ◽  
Cost Of Energy ◽  
Isometric Muscle Contraction ◽  
Eccentric Muscle Contraction ◽  
Energy Consuming ◽  
Downhill Walking ◽  
Voluntary Contractions ◽  
Muscle Actions

Physiological changes in musculature allow widespread movements in human body. Correspondingly, varying in muscle prototypes characterise direct different training paradigms in therapeutics practice or can governs athletic performances. Mode of muscle contraction type are isometric, concentric or eccentric. Great examples of concentric exercise are walking- up-hill, stair ascent and lifting a dumbbell in bicep curl or pushing a bar up. Examples of eccentric muscle actions are walking - down-hill, satire decent and, isokinetic arm and leg extensions. During isometric muscle contraction the length of muscle does not change while muscle exert force .This type of movement can be seen while a person performs a maximal voluntary contractions (MVCs).Eccentric exercises increasing the concentric and isometric contraction as well. Performing the eccentric muscle contraction in daily life enhance quality of life and lifespan due to increasing muscle strength with low cost of energy consuming and thus it can apply in variety of domains. A simple walking task such as downhill - walking (i.e. 30 min) can provide the aforementioned conditions.

scholarly journals Actomyosin energy turnover declines while force remains constant during isometric muscle contraction

2004 ◽  
Vol 555 (1) ◽  
pp. 27-43 ◽  
Author(s):  
Timothy G. West ◽  
N. A. Curtin ◽  
Michael A. Ferenczi ◽  
Zhen-He He ◽  
Yin-Biao Sun ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Energy Turnover ◽  
Isometric Muscle Contraction ◽  
Isometric Muscle

scholarly journals Feature Identification for Non-Intrusively Extracting Occupant Energy-Use Information in Office Buildings

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Hamed Nabizadeh Rafsanjani
Keyword(s):  
Capital Investment ◽  
Energy Use ◽  
Low Cost ◽  
Specific Energy Consumption ◽  
Cost Effective ◽  
Office Buildings ◽  
Specific Power ◽  
Feature Identification ◽  
Load Monitoring ◽  
Energy Consuming

Detailed energy-use information of office buildings’ occupants is necessary to implement proper simulation/intervention techniques. However, acquiring accurate occupant-specific energy consumption in office buildings at low cost is currently a challenging task since existing intrusive load monitoring (ILM) technologies require a large capital investment to provide high-resolution electricity usage data for individual occupants. On the other hand, non-intrusive load monitoring (NILM) approaches have been proven as more cost effective and flexible approaches to provide energy-use information of individual appliances. Therefore, extending the concept of NILM to individual occupants would be beneficial. This paper proposes two occupancy-related energy-consuming features, delay interval and magnitude of power changes and evaluates their significances for extracting occupant-specific power changes in a non-intrusive manner. The proposed features were examined through implementing a logistic regression model as a predictor on aggregate energy load data collected from an office building. Hypotheses tests also confirmed that both features are statistically significant to non-intrusively derive individual occupants’ energy-use information. As the main contribution of this study, these features could be utilized in developing sophisticated NILM-based approaches to monitor individual occupant energy-consuming behavior.  

scholarly journals Combined diffusion and strain tensor MRI reveals a heterogeneous, planar pattern of strain development during isometric muscle contraction

2011 ◽  
Vol 300 (5) ◽  
pp. R1079-R1090 ◽  
Author(s):  
Erin K. Englund ◽  
Christopher P. Elder ◽  
Qing Xu ◽  
Zhaohua Ding ◽  
Bruce M. Damon
Keyword(s):  
Muscle Contraction ◽  
Muscle Fiber ◽  
Diffusion Tensor ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Fiber Direction ◽  
Strain Pattern ◽  
Isometric Muscle Contraction ◽  
Diffusion Tensors

The purposes of this study were to create a three-dimensional representation of strain during isometric contraction in vivo and to interpret it with respect to the muscle fiber direction. Diffusion tensor MRI was used to measure the muscle fiber direction of the tibialis anterior (TA) muscle of seven healthy volunteers. Spatial-tagging MRI was used to measure linear strains in six directions during separate 50% maximal isometric contractions of the TA. The strain tensor (E) was computed in the TA's deep and superficial compartments and compared with the respective diffusion tensors. Diagonalization of E revealed a planar strain pattern, with one nonzero negative strain (εN) and one nonzero positive strain (εP); both strains were larger in magnitude ( P < 0.05) in the deep compartment [εN = −40.4 ± 4.3%, εP = 35.1 ± 3.5% (means ± SE)] than in the superficial compartment (εN = −24.3 ± 3.9%, εP = 6.3 ± 4.9%). The principal shortening direction deviated from the fiber direction by 24.0 ± 1.3° and 39.8 ± 6.1° in the deep and superficial compartments, respectively ( P < 0.05, deep vs. superficial). The deviation of the shortening direction from the fiber direction was due primarily to the lower angle of elevation of the shortening direction over the axial plane than that of the fiber direction. It is concluded that three-dimensional analyses of strain interpreted with respect to the fiber architecture are necessary to characterize skeletal muscle contraction in vivo. The deviation of the principal shortening direction from the fiber direction may relate to intramuscle variations in fiber length and pennation angle.

scholarly journals Diazoxide and Exercise Enhance Muscle Contraction during Obesity by Decreasing ROS Levels, Lipid Peroxidation, and Improving Glutathione Redox Status

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1232
Author(s):  
Mariana Gómez-Barroso ◽  
Koré M. Moreno-Calderón ◽  
Elizabeth Sánchez-Duarte ◽  
Christian Cortés-Rojo ◽  
Alfredo Saavedra-Molina ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Lipid Peroxidation ◽  
Muscle Contraction ◽  
Katp Channel ◽  
Metabolic Stress ◽  
Muscular Contraction ◽  
Redox Status ◽  
Glutathione Redox ◽  
Katp Channel Openers

Obesity causes insulin resistance and hyperinsulinemia which causes skeletal muscle dysfunction resulting in a decrease in contraction force and a reduced capacity to avoid fatigue, which overall, causes an increase in oxidative stress. KATP channel openers such as diazoxide and the implementation of exercise protocols have been reported to be actively involved in protecting skeletal muscle against metabolic stress; however, the effects of diazoxide and exercise on muscle contraction and oxidative stress during obesity have not been explored. This study aimed to determine the effect of diazoxide in the contraction of skeletal muscle of obese male Wistar rats (35 mg/kg), and with an exercise protocol (five weeks) and the combination from both. Results showed that the treatment with diazoxide and exercise improved muscular contraction, showing an increase in maximum tension and total tension due to decreased ROS and lipid peroxidation levels and improved glutathione redox state. Therefore, these results suggest that diazoxide and exercise improve muscle function during obesity, possibly through its effects as KATP channel openers.

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