scholarly journals Behaviour of motor units of human arm muscles: differences between slow isometric contraction and relaxation.

1985 ◽  
Vol 359 (1) ◽  
pp. 107-118 ◽  
Author(s):  
J J Denier van der Gon ◽  
B M ter Haar Romeny ◽  
E J van Zuylen
Keyword(s):  
Isometric Contraction ◽  
Motor Units ◽  
Human Arm ◽  
Arm Muscles ◽  
Contraction And Relaxation

scholarly journals The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study)

2016 ◽  
Vol 7 ◽  
Author(s):  
Tomasz Tomiak ◽  
Tetiana I. Abramovych ◽  
Andriy V. Gorkovenko ◽  
Inna V. Vereshchaka ◽  
Viktor S. Mishchenko ◽  
...  
Keyword(s):  
Human Arm ◽  
Arm Muscles ◽  
Preliminary Study ◽  
Emg Patterns

Is there altered activity of dorsal neck muscles during isometric contraction of arm muscles in individuals with chronic neck pain?

Physiotherapy ◽  
2015 ◽  
Vol 101 ◽  
pp. e1251
Author(s):  
L. Rahnama ◽  
A. Rezasoltani ◽  
N. Karimi ◽  
F. Noori-Kochi ◽  
M. Saberi ◽  
...  
Keyword(s):  
Neck Pain ◽  
Isometric Contraction ◽  
Chronic Neck Pain ◽  
Neck Muscles ◽  
Arm Muscles

Regulation of 3D Human Arm Impedance Through Muscle Co-Contraction

2013 ◽  
Author(s):  
Harshil Patel ◽  
Gerald O’Neill ◽  
Panagiotis Artemiadis
Keyword(s):  
Dimensional Space ◽  
Human Subjects ◽  
Three Dimensional ◽  
Mechanical Impedance ◽  
Dominant Factor ◽  
Robot Arm ◽  
End Point ◽  
Human Arm ◽  
Arm Muscles ◽  
Experimental Trials

Humans have the inherent ability of performing highly dexterous and skillful tasks with their arms, involving maintenance of posture, movement, and interaction with the environment. The latter requires the human to control the dynamic characteristics of the upper limb musculoskeletal system. These characteristics are quantitatively represented by inertia, damping, and stiffness, which are measures of mechanical impedance. Many previous studies have shown that arm posture is a dominant factor in determining the end point impedance on a horizontal (transverse) plane. This paper presents the characterization of the end point impedance of the human arm in three-dimensional space. Moreover, it models the regulation of the arm impedance with respect to various levels of muscle co-contraction. The characterization is made by route of experimental trials where human subjects maintained arm posture while their arms were perturbed by a robot arm. Furthermore, the subjects were asked to control the level of their arm muscles’ co-contraction, using visual feedback of their muscles’ activation, in order to investigate the effect of this muscle co-contraction on the arm impedance. The results of this study show a very interesting, anisotropic increase of arm stiffness due to muscle co-contraction. These results could lead to very useful conclusions about the human’s arm biomechanics, as well as many implications for human motor control-specifically the control of arm impedance through muscle co-contraction.

EMG Controlled Soft Robotic Bicep Augmentation

2019 ◽  
Author(s):  
Jiayue Zhang ◽  
Daniel Vanderbilt ◽  
Ethan Fitz ◽  
Janet Dong
Keyword(s):  
Hybrid Control ◽  
Biceps Brachii ◽  
Pressure Sensors ◽  
Industrial Workers ◽  
Pneumatic Muscle ◽  
Repetitive Lifting ◽  
Human Arm ◽  
Lifting Capacity ◽  
Arm Muscles ◽  
Repetitive Loading

Abstract Repeated lifting tasks are often required of industrial workers. Such repetitive loading of workers’ arms throughout the workday can lead to injury and fatigue. This paper details the development and prototyping of a wearable soft robotic device to augment a worker’s arms by sensing and mimicking the contractions of their arm muscles. The device shares lifting loads with the user’s muscles to increase their lifting capacity, thereby preventing injury and reducing fatigue. The human arm contains many muscles that coordinate to produce movement. However, as a simplified proof of concept, this project developed a prototype to augment just the biceps brachii muscle since it is the primary pulling muscle used in lifting movements. Key components of the prototype include a soft robotic actuator analogous to the biceps, a control system for the actuator, and a method of attaching the actuator to the user’s arm. The McKibben-inspired pneumatic muscle was chosen as the soft actuator of the prototype. The Electromyography (EMG) and pressure sensors are used to inform a hybrid control algorithm combining PID and model-based control methods. The method and results of the design and preliminary feasibility testing of the pneumatic muscle, the controlling algorithm, and the overall prototype are discussed in this paper. Based on these results, a wearable EMG controlled soft robotic arm augmentation could feasibly increase the endurance of industrial workers performing repetitive lifting tasks.

447 Assessing Isometric Contraction and Relaxation Using Esophageal Pressure Topography

2016 ◽  
Vol 150 (4) ◽  
pp. S95-S96
Author(s):  
Yinglian Xiao ◽  
Dustin A. Carlson ◽  
Zhiyue Lin ◽  
Nicolas Rinella ◽  
Min-hu Chen ◽  
...  
Keyword(s):  
Isometric Contraction ◽  
Esophageal Pressure ◽  
Contraction And Relaxation

scholarly journals Simple Asana: Yoga and the Elderly

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Park SY ◽  
◽  
Vigneswaran WT ◽  
Keyword(s):  
Young People ◽  
Isometric Contraction ◽  
Simple Form ◽  
The Elderly ◽  
Alternative Form ◽  
Yoga Practice ◽  
Breathing Exercise ◽  
Weight Problems ◽  
Muscle Groups ◽  
Contraction And Relaxation

Yoga is becoming very popular among young people, however it is also exceptionally beneficial for the elderly to improve mobility, strength and combat chronic ailments. It is an alternative form of medicine and can be ancillary tool for treating pain, cardiovascular issues, weight problems, depression, sleep disorders and many more. The practice goal of yoga is to challenge oneself but not be overwhelmed, develop inner awareness without judgement. In contrast to many other programs it does not involve strenuous workouts or expensive equipment and is not competitive. The simple form involves series of static positions that use isometric contraction and relaxation of different muscle groups to create specific body alignments with coordinated breathing and deep meditative relaxation. The best yoga practice for elderly or a person with limitations are that uses supporting props as blankets, pillows or chairs during asana to overcome the limitations that are coordinated with breathing exercise and meditation.

Cyclic production of tension force in the plasmodial strand of Physarum polycephalum and its relation to microfilament morphology

1978 ◽  
Vol 33 (1) ◽  
pp. 205-225
Author(s):  
R. Nagai ◽  
R.N. Yoshimoto ◽  
N. Kamiya
Keyword(s):  
Isometric Contraction ◽  
Physarum Polycephalum ◽  
Isotonic Contraction ◽  
Cyclic Contraction ◽  
Aggregation Pattern ◽  
Cyclic Changes ◽  
Contraction And Relaxation ◽  
Elongation Phase ◽  
Contraction Cycle ◽  
Isotonic Contractions

Cyclic contraction and relaxation of plasmodial strands of Physarum polycephalum were measured under both isotonic and isometric conditions, and their relation to changes in microfilament (MF) morphology was investigated. The contraction-relaxation rhythm of a strand segment was insignificant and irregular immediately after isolation from the mother plasmodium. It became regular half an hour later when local minute rhythms were synchronized spontaneously. If a strand kept under isotonic conditions was loaded with a heavier weight or a strand kept under isometric conditions was stretched a few times, the amplitude of each contraction wave was enhanced. After a strand had been thus conditioned, it was fixed at a selected phase of the contraction-relaxation cycle under both isotonic and isometric conditions. The state of MFs changed strikingly according to the phase of the contraction cycle. In the shortening phase of the strand under isotonic contractions, MFs with a diameter of 6–7 nm were arranged parallel to each other to form large compact bundles in which adjacent filaments were bridged with cross linkages. Among these MFs, thicker filaments were sporadically scattered. At about the phase of minimal strand length, most of the MFs became kinky and formed networks. In the elongating phase, new loose bundles of MFs developed from the network. These loose bundles became compact again when the strand reached its maximal elongation phase. In the isometric contraction, MFs in the increasing tension phase were nearly the same as those in the shortening phase in isotonic contraction. Around the maximal tension phase, dense areas of MFs appeared along the bundles in place of the network formed in the isotonic contraction phase. These areas were closely packed, with MFs arranged parallel to each other. In the decreasing and minimal tension phases in isometric contraction, MFs were arranged similarly to those in the elongating and maximally elongated phases, respectively, in isotonic contraction. Alternation between the straight bundle and fine network configuration of the MFs observed in isotonic contraction was inconspicuous in isometric contraction. This was probably due to spatial restriction of shortening under isometric contraction. The results are interpreted in terms of cyclic changes of the aggregation pattern of the MFs in the form of F-actin, as opposed to the possibility that the contraction-relaxation cycles depend on cyclic G-F transformation of actin.

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