The Relationship Between EMG-Time and Isometric Force-Time Curves

2002 ◽  
Vol 34 (5) ◽  
pp. 22
Author(s):  
Loren Z.F. Chiu ◽  
Andrew C. Fry ◽  
Brian K. Schilling ◽  
Lawrence W. Weiss ◽  
Richard B. Kreider
Keyword(s):  
Isometric Force ◽  
Force Time ◽  
The Relationship

The Relationship Between Isometric Force-Time Curve Characteristics and Club Head Speed in Recreational Golfers

2012 ◽  
Vol 26 (10) ◽  
pp. 2685-2697 ◽  
Author(s):  
Brian K. Leary ◽  
Jason Statler ◽  
Britton Hopkins ◽  
Rachael Fitzwater ◽  
Tucker Kesling ◽  
...  
Keyword(s):  
Isometric Force ◽  
Time Curve ◽  
Club Head ◽  
Force Time ◽  
The Relationship ◽  
Recreational Golfers

scholarly journals The Relationship between Isometric Force-Time Characteristics and Dynamic Performance: A Systematic Review

Sports ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 63 ◽  
Author(s):  
Danny Lum ◽  
G. Gregory Haff ◽  
Tiago M. Barbosa
Keyword(s):  
Isometric Force ◽  
Dynamic Performance ◽  
Lower Limbs ◽  
Upper Body ◽  
Original Research ◽  
Dynamic Performances ◽  
Time Variables ◽  
Force Time ◽  
The Relationship ◽  
Body Dynamic

The purpose of this article was to review the data on the relationship between multi-joint isometric strength test (IsoTest) force-time characteristics (peak force, rate of force development and impulse) and dynamic performance that is available in the current literature. Four electronic databases were searched using search terms related to IsoTest. Studies were considered eligible if they were original research studies that investigated the relationships between multi-joint IsoTest and performance of dynamic movements; published in peer-reviewed journals; had participants who were athletes or active individuals who participate in recreational sports or resistance training, with no restriction on sex; and had full text available. A total of 47 studies were selected. These studies showed significant small to large correlations between isometric bench press (IBP) force-time variables and upper body dynamic performances (r2 = 0.221 to 0.608, p < 0.05) and significant small to very large correlation between isometric squat (ISqT) (r2 = 0.085 to 0.746, p < 0.05) and isometric mid-thigh pull (IMTP) (r2 = 0.120 to 0.941, p < 0.05) force-time variables with lower body dynamic performances. IsoTest force-time characteristics were shown to have small to very large correlations with dynamic performances of the upper and lower limbs as well as performance of sporting movements (r2 = 0.118 to 0.700, p < 0.05). These data suggest that IsoTest force-time characteristics provide insights into the force production capability of athletes which give insight into dynamic performance capabilities.

Oxytocin-mediated recruitment of slowly cycling cross bridges and isometric force in rat myometrium

1996 ◽  
Vol 270 (2) ◽  
pp. E203-E208
Author(s):  
A. L. Ruzycky ◽  
B. T. Ameredes
Keyword(s):  
Isometric Force ◽  
Additional Stress ◽  
Shortening Velocity ◽  
Cycling Rate ◽  
Quick Release ◽  
Cross Bridge ◽  
Cross Bridges ◽  
Unit Stress ◽  
Release Method ◽  
The Relationship

The relationship between cross-bridge cycling rate and isometric stress was investigated in rat myometrium. Stress production by myometrial strips was measured under resting, K+ depolarization, and oxytocin-stimulated conditions. Cross-bridge cycling rates were determined from measurements of maximal unloaded shortening velocity, using the quick-release method. Force redevelopment after the quick release was used as an index of cross-bridge attachment. With maximal K+ stimulation, stress increased with increased cross-bridge cycling (+76%; P < 0.05) and attached cross bridges (+112%; P < 0.05). Addition of oxytocin during K+ stimulation further increased stress (+30%; P < 0.05). With this force component, the cross-bridge cycling rate decreased (-60%; P < 0.05) similar to that under resting conditions. Attached cross-bridges did not increase with this additional stress. The results suggest two distinct mechanisms mediating myometrial contractions. One requires elevated intracellular calcium and rapidly cycling cross bridges. The other mechanism may be independent of calcium and appears to be mediated by slowly cycling cross bridges, supporting greater unit stress.

scholarly journals Effect of Multi-Impact on QIQH Carbon/Epoxy Composite Laminate

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 511
Author(s):  
Adadé Seyth Ezéckiel Amouzou ◽  
Olivier Sicot ◽  
Ameur Chettah ◽  
Shahram Aivazzadeh
Keyword(s):  
Composite Structures ◽  
Epoxy Composite ◽  
Impact Damage ◽  
Ultrasonic Control ◽  
Impact Tests ◽  
Post Impact ◽  
Testing Techniques ◽  
Force Time ◽  
The Relationship ◽  
Force Displacement

This work is motivated by increasingly used of composite structures under severe loading conditions. During their use, these materials are often subjected to impact as for example, in the aeronautical field the fall of hailstone on structure composites. In fact, the low energy traditional impact tests don’t allow to see the evolution of the damage and don’t permit also to compare the best tolerance to impact between different stratifications. The multi-impact tests made it possible to find a solution to this problem. In this work, multi-impact tests are performed on three carbon/epoxy stratifications. The final goal is to predict the durability of the composite structures during impact loading for their design. This study brings to light the response of multi-impact tests through force-time and force-displacement curves obtained experimentally. On the other hand, a parameter D has introduced following the experimental results. This made it possible to rank the three stratifications from their tolerance to multi-impact tests. To evaluate the post impact damage, ultrasonic testing techniques are used. The results allow to find the relationship between the damaged surface obtained by the ultrasonic control and the parameter D and to rank the three laminates configurations.

scholarly journals Influence of muscle length on work from trabecular muscle of frog atrium and ventricle.

1995 ◽  
Vol 198 (10) ◽  
pp. 2221-2227 ◽  
Author(s):  
D A Syme ◽  
R K Josephson
Keyword(s):  
Isometric Force ◽  
Muscle Length ◽  
Work Capacity ◽  
Linear Increase ◽  
Ventricular Muscle ◽  
Work Output ◽  
Loop Technique ◽  
Work Done ◽  
The Relationship ◽  
Work Loop

The work capacity of segments of atrial and ventricular muscle from the frog Rana pipiens was measured as a function of muscle length using the work loop technique. Both the work done during shortening and the work required to re-lengthen the muscle after shortening increased with muscle length. Net work increased with length up to a maximum, beyond which work declined. The optimum sarcomere length for work output was 2.5-2.6 microns for both atrial and ventricular muscle. Isometric force increased with muscle length to lengths well beyond the optimum for work output. Thus, the decline in work at long lengths is not simply a consequence of a reduction in the capacity of heart muscle to generate force. It is proposed that it is the non-linear increase in work required to re-lengthen muscle with increasing muscle length which limits net work output and leads to a maximum in the relationship between net work and muscle length. Extension of the results from muscle strips to intact hearts suggests that the work required to fill the ventricle exceeds that available from atrial muscle at all but rather short ventricular muscle lengths.

Wedge Bond Process Optimization Method for 1.5 mil Al Wire on Al Bond Pad

2015 ◽  
Vol 2015 (1) ◽  
pp. 000413-000418
Author(s):  
Wenjuan Qi ◽  
Daniel D. Evans
Keyword(s):  
Process Development ◽  
Optimization Method ◽  
Black Ring ◽  
Basic Relationship ◽  
Force Time ◽  
Bond Pads ◽  
Wedge Bonding ◽  
The Relationship ◽  
Inputs And Outputs

Modern wedge bonders have evolved since their early inception in 1957. This paper will review the common challenges process engineers face when selecting a wedge bond machine configuration and developing robust processes. Wedge bond cases presented will show the tradeoff between process inputs and the resulting bond shapes, bond appearance of black ring, burrs, pull results, etc. The purpose of this work was to optimize the process outputs: bond shape, black ring, burrs, and pulls on a die with aluminum bond pads. Process inputs included Force, Time, and Ultrasonic Level. An aluminum wafer was used to understand the basic relationship between process parameter inputs and outputs. The learning was then applied to a die with aluminum bond pads. Examples of non-compliance and compliance will be shown to help process engineers evaluate wedge bonds and make refinements. The case studied was for an aluminum bond pad/Al wafer and 1.5 mil aluminum wire interaction that creates burrs around the bond (wire to pad interface), black ring on the bond periphery (wedge tool to wire interface) and the resulting pulls. Both the graphical and numerical results of the case study have clearly demonstrated the relationship between the typical process inputs and outputs, particularly bond shape, burrs, black ring and pulls. The findings in this study will provide a general guideline and a troubleshooting reference for wedge bonding process development.

Reliability of Maximum Isometric Force-Time Parameters during a Leg Press Test in Pubertal Basketball Players

2002 ◽  
Vol 14 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Panagiotis Ioakimidis ◽  
Vasilios Gerodimos ◽  
Eleftherios Kellis ◽  
Spiros Kellis
Keyword(s):  
Isometric Force ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Basketball Players ◽  
Leg Press ◽  
Maximal Force ◽  
Maximum Isometric Force ◽  
Time Parameters ◽  
Relative Scale ◽  
Force Time

Fifteen young basketball players (aged 14.4 – 0.5 yrs) underwent two identical testing sessions spaced one week apart, to determine the reliability of maximum isometric force and force-time parameters during a maximal bilateral isometric leg press effort. The maximal isometric force (MIF), the ratio of maximal force to time (TMIF) to attain maximal force (ARMIF), starting strength (F50), and on a relative scale the time taken to increase the force from 10% to 30%, 60%, and 90% of maximal force were calculated. High intraclass correlation coefficients (ICC) were found for MIF (0.96), ARMIF (0.85), and F50 (0.90). On the relative scale, the ICCs for the times to produce 30%, 60%, and 90% of maximum force were 0.94, 0.95, 0.95, respectively. The present results indicate that maximum isometric force and the force-time parameters during a bilateral leg press can be measured reliably in pubertal basketball players.

Relationship Between Isometric Force–Time Characteristics and Sprint Kayaking Performance

2020 ◽  
pp. 1-6
Author(s):  
Danny Lum ◽  
Abdul Rashid Aziz
Keyword(s):  
Bench Press ◽  
Isometric Force ◽  
Rate Of Force Development ◽  
Isometric Strength ◽  
Mean Power ◽  
Force Development ◽  
Peak Rate ◽  
Time To Completion ◽  
Strength Tests ◽  
Force Time

Force–time characteristics obtained during isometric strength tests are significantly correlated to various sporting movements. However, data on the relationship between isometric force–time characteristics and sprint kayaking performance are lacking in the literature. Purpose: The purpose of the study was, therefore, to investigate the relationship between sprint kayaking performance with ergometer performance and measures from 3 isometric strength tests: isometric squat, isometric bench press, and isometric prone bench pull. Methods: A total of 23 sprint kayaking athletes performed all 3 tests, at 90° and 120° knee angles for isometric squat and at elbow angles for isometric bench press and isometric prone bench pull, and a 200-m sprint on-water to attain the fastest time-to-completion (OWTT) possible and on a kayak ergometer to attain the highest mean power (LABTT) possible. Results: There was a significant inverse correlation between OWTT and LABTT (r = −.90, P < .001). The peak forces achieved from all isometric strength tests were significantly correlated with time-to-completion for OWTT and mean power for LABTT (r = −.44 to −.88, P < .05 and .47 to .80, P < .05, respectively). OWTT was significantly correlated with the peak rate of force development during all isometric tests except for the isometric squat at a 120° knee angle (r = −.47 to −.62, P < .05). LABTT was significantly correlated with peak rate of force development from the isometric bench press and isometric prone bench pull (r = .64–.86, P < .01). Conclusion: Based on the observed strong correlations, the mean power attained during LABTT is a good predictor of OWTT time-to-completion. Furthermore, upper- and lower-body maximum strength and peak rate of force development are equally important for on-water and ergometer sprint kayaking performance.

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