Simulation Study on the Effects of Adaptive Time for Assist Considering Release of Isometric Force During Elbow Flexion

2018 ◽  
pp. 347-350
Author(s):  
Jeewon Choi ◽  
Ping Yeap Loh ◽  
Satoshi Muraki
Keyword(s):  
Simulation Study ◽  
Isometric Force ◽  
Elbow Flexion ◽  
Adaptive Time

scholarly journals Muscle function in avian flight: achieving power and control

2011 ◽  
Vol 366 (1570) ◽  
pp. 1496-1506 ◽  
Author(s):  
Andrew A. Biewener
Keyword(s):  
Energy Savings ◽  
Isometric Force ◽  
Large Fraction ◽  
Body Movement ◽  
Fibre Length ◽  
Elbow Flexion ◽  
Flapping Flight ◽  
Whole Body ◽  
Flight Muscles ◽  
Wing Stroke

Flapping flight places strenuous requirements on the physiological performance of an animal. Bird flight muscles, particularly at smaller body sizes, generally contract at high frequencies and do substantial work in order to produce the aerodynamic power needed to support the animal's weight in the air and to overcome drag. This is in contrast to terrestrial locomotion, which offers mechanisms for minimizing energy losses associated with body movement combined with elastic energy savings to reduce the skeletal muscles' work requirements. Muscles also produce substantial power during swimming, but this is mainly to overcome body drag rather than to support the animal's weight. Here, I review the function and architecture of key flight muscles related to how these muscles contribute to producing the power required for flapping flight, how the muscles are recruited to control wing motion and how they are used in manoeuvring. An emergent property of the primary flight muscles, consistent with their need to produce considerable work by moving the wings through large excursions during each wing stroke, is that the pectoralis and supracoracoideus muscles shorten over a large fraction of their resting fibre length (33–42%). Both muscles are activated while being lengthened or undergoing nearly isometric force development, enhancing the work they perform during subsequent shortening. Two smaller muscles, the triceps and biceps, operate over a smaller range of contractile strains (12–23%), reflecting their role in controlling wing shape through elbow flexion and extension. Remarkably, pigeons adjust their wing stroke plane mainly via changes in whole-body pitch during take-off and landing, relative to level flight, allowing their wing muscles to operate with little change in activation timing, strain magnitude and pattern.

Maximal Voluntary Isometric Elbow Flexion Force during Unilateral versus Bilateral Contractions in Individuals with Chronic Stroke

2008 ◽  
Vol 24 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Kevin McQuade ◽  
Michelle L. Harris-Love ◽  
Jill Whitall
Keyword(s):  
Isometric Force ◽  
Force Production ◽  
Elbow Flexion ◽  
Chronic Stroke ◽  
Total Force ◽  
Elbow Flexors ◽  
Task Conditions ◽  
Isometric Force Production ◽  
Flexion Force ◽  
Maximal Isometric Force

The purpose of this study was to determine whether the phenomenon of bilateral deficit in muscular force production observed in healthy subjects and mildly impaired stroke patients also exists in patients with more chronic and greater levels of stroke impairment. Ten patients with chronic hemiparesis resulting from stroke performed unilateral and bilateral maximal voluntary isometric contractions of the elbow flexors. When the total force produced by both arms was compared, 12% less force was produced in the bilateral compared with unilateral condition (p= 0.01). However, studying the effect of task conditions on each arm separately revealed a significant decline in nonparetic (p= 0.01) but not paretic elbow flexor force in the bilateral compared with unilateral condition. Results suggest that a significant bilateral force deficit exists in the nonparetic but not the paretic arm in individuals with chronic stroke. Bilateral task conditions do not seem to benefit or impair paretic arm maximal isometric force production in individuals with moderate-severity chronic stroke.

Body Roll and Handpath in Freestyle Swimming: A Computer Simulation Study

1993 ◽  
Vol 9 (3) ◽  
pp. 227-237 ◽  
Author(s):  
James G. Hay ◽  
Qi Liu ◽  
James G. Andrews
Keyword(s):  
Computer Simulation ◽  
Simulation Study ◽  
Sagittal Plane ◽  
Elbow Flexion ◽  
Flexion Angle ◽  
Computer Simulation Study ◽  
Hinge Joint ◽  
Body Roll ◽  
Competitive Swimmers

The purpose of this study was to determine the effect that body roll has on the path followed by the hand during the pull phase in freestyle swimming. The trunk and right arm were modeled as two rigid segments joined at the shoulder by a simple hinge joint. The arm segment was assigned an elbow flexion angle, and the hand was made to move in a plane through the shoulder parallel to the sagittal plane of the rotating trunk. Shoulder extension and trunk roll occurred simultaneously at selected rates. Medial deviations of the hand to the midline of the trunk can be obtained with body roll alone and require less roll than is usually observed among competitive swimmers. When body roll exceeds the amount necessary to produce the desired medial deviation of the hand, the swimmer must move the arm away from, rather than toward, the trunk's midline.

scholarly journals The Relationship Between Speed and Strength in the Beach Volleyball Serve

2021 ◽  
Vol 80 (1) ◽  
pp. 39-47
Author(s):  
Mario Terol-Sanchis ◽  
Carlos Elvira-Aranda ◽  
María José Gomis-Gomis ◽  
José Antonio Pérez-Turpin
Keyword(s):  
Internal Rotation ◽  
Isometric Force ◽  
Body Height ◽  
Elbow Flexion ◽  
Knee Extension ◽  
Wrist Flexion ◽  
Shoulder Flexion ◽  
Hand Dynamometer ◽  
Highly Correlated ◽  
The Relationship

Abstract The objective of this study was to analyze the relationship between isometric force produced in different joints and its effects on the power kick serve speed in beach volleyball as a predictive aspect to improve sports performance. Seven athletes competing at national and international levels (mean ± standard deviation; age: 21.6 ± 3.20 years; body height: 1.87 ± 0.08 cm; body mass 80.18 ± 7.11 kg) were evaluated using maximum isometric force contractions (i.e., spinal and knee extension, grip by a hand dynamometer (handgrip), internal shoulder rotation, shoulder flexion, elbow flexion and extension, and wrist flexion). Speed of the ball was recorded with a pistol radar and force was measured with a strain gauge. Results showed a relationship between isometric force developed in the internal rotation of the shoulder and speed of the ball (r = 0.76*; p < 0.05). In the remaining isometric exercises, positive low to moderate correlations were found in the spine and knee extension (r = 0.56; p = 0.200) and elbow flexion (r = 0.41; p = 0.375). On the other hand, the remaining isometric exercises obtained weak or non-significant correlations. Force developed in the internal rotation of the shoulder highly correlated with the speed of the power kick, explaining, together with the elbow flexion and the extension of the knee and back, much of the variability of the power kick of beach volleyball athletes.

scholarly journals The Effects of Differences in the Morphologies of the Ulnar Collateral Ligament and Common Tendon of the Flexor-Pronator Muscles on Elbow Valgus Braking Function: A Simulation Study

2021 ◽  
Vol 18 (4) ◽  
pp. 1986
Author(s):  
Masahiro Ikezu ◽  
Mutsuaki Edama ◽  
Takuma Inai ◽  
Kanta Matsuzawa ◽  
Fumiya Kaneko ◽  
...  
Keyword(s):  
Simulation Study ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Average Strain ◽  
Collateral Ligament ◽  
Group Iii ◽  
Valgus Angle ◽  
Group I ◽  
Independent Form ◽  
Group Ii

The anterior bundle (AB) and posterior bundle (PB) of the ulnar collateral ligament and the anterior common tendon (ACT) and posterior common tendon (PCT) of the flexor-pronator muscles have an independent form and an unclear form. The purpose of this study was to clarify the effect of differences in the morphologies of the AB, PB, ACT, and PCT on the elbow valgus braking function. This investigation examined three elbows. In the classification method, the AB, PB, ACT, and PCT with independent forms constituted Group I; the AB, ACT, and PCT with independent forms and the PB with an unclear form constituted Group II; the AB, PB, ACT, and PCT with unclear forms constituted Group III. The strains were calculated by simulation during elbow flexion at valgus at 0° and 10°. At 0° valgus, Group I and Group II showed similar AB and PCT strain patterns, but Group III was different. At 10° valgus, most ligaments and tendons were taut with increasing valgus angle. The average strain patterns of all ligaments and tendons were similar for the groups. The AB, PB, ACT, and PCT may cooperate with each other to contribute to valgus braking.

The Effect of Training Volume on the Acute Response and Adaptations to Resistance Training

2006 ◽  
Vol 1 (2) ◽  
pp. 108-121 ◽  
Author(s):  
Jason Brandenburg ◽  
David Docherty
Keyword(s):  
Resistance Exercise ◽  
Blood Lactate ◽  
Isometric Force ◽  
Elbow Flexion ◽  
Constant Load ◽  
Single Session ◽  
Threshold Response ◽  
Acute Response ◽  
Before And After ◽  
Maximal Isometric Force

Purpose:To examine the acute response to 2 resistance-exercise protocols performed to repetition failure, but different in load configuration, and determine whether the acute response was related to strength increases after 8 weeks of training.Methods:Eighteen resistance-trained men completed a single session of 2 resistance-exercise protocols. The constant-load protocol (CL) required subjects to complete 3 sets of single-arm preacher curls (elbow flexion) to failure using a load of ~77% 1RM. The reduced-load protocol (RL) was similar, but training load was reduced for the second and third sets. Maximal isometric force (MVIC) and blood lactate were assessed preprotocol and postprotocol to determine the acute response. For the 8-week training phase, subjects (N = 12) were divided into 2 programs, each corresponsing to 1 of the protocols. Strength was measured before and after training.Results:MVIC decreased from 106.2 ± 13.8 to 84.3 ± 12.1 N · m and from 109.1 ± 14.7 to 82.5 ± 13 N · m after the CL and RL protocols, respectively. The decrements in MVIC were significant (P < .001), with the decline after RL tending to be greater (P = .051). Postprotocol blood lactate concentrations after CL and RL were 3.4 ± 1.1 and 4.1 ± 1.3 mmol/L, respectively, with greater increases after RL (P = .036). Similar and significant 1RM strength increases were observed after both programs (from 20.7 ± 2.7 to 23.3 ± 3.5 kg after CL and from 22.4 ± 2.9 to 25.5 ± 3.2 kg after RL; P < .001).Conclusion:The similar increases in strength suggest that either the greater acute response to RL was not related to the increases in strength or a minimal (threshold) response was achieved during both programs.

How Accurately Can Elbow Flexion Force Be Estimated?

1989 ◽  
Vol 68 (3_suppl) ◽  
pp. 1159-1162 ◽  
Author(s):  
Richard W. Bohannon ◽  
Noreen Endemann
Keyword(s):  
Isometric Force ◽  
Elbow Flexion ◽  
Muscular Force ◽  
Independent Variables ◽  
Maximum Isometric Force ◽  
Young Subjects ◽  
Flexion Force

The purpose of this study was to determine how accurately healthy young subjects could produce a muscular force that was 50% of their maximum and to determine the influence of several independent variables on the accuracy. On each of three nonconsecutive days, 14 men and 19 women (18 to 46 yr. old) performed three maximal elbow-flexion efforts and three efforts that they estimated to be 50% of their maximum. Isometric force was measured with a hand-held dynamometer. The estimated forces ranged from 18.3 to 81.7% of maximum. The error in force from 50% was related to whether the dominant or nondominant extremity was tested, but it was unrelated to whether maximal or submaximal efforts were performed first and to the day of testing. When the accurate generation of a submaximal force is required, naive subjects may require feedback.

A Monte Carlo simulation study of associated liquid crystals

1999 ◽  
Vol 97 (11) ◽  
pp. 1173-1184 ◽  
Author(s):  
R. Berardi, M. Fehervari, C. Zannoni
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Liquid Crystals ◽  
Simulation Study ◽  
Monte Carlo Simulation Study
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