Examining Impulse-Variability in Kicking

Motor Control ◽  
2016 ◽  
Vol 20 (3) ◽  
pp. 222-232 ◽  
Author(s):  
Andrew Chappell ◽  
Sergio L. Molina ◽  
Jonathon McKibben ◽  
David F. Stodden
Keyword(s):  
Repeated Measures ◽  
Maximum Speed ◽  
Spatial Accuracy ◽  
Spatial Error ◽  
Trade Off ◽  
Old Adults ◽  
Radial Error ◽  
Skill Performance ◽  
Impulse Variability ◽  
Speed Accuracy

This study examined variability in kicking speed and spatial accuracy to test the impulse-variability theory prediction of an inverted-U function and the speed-accuracy trade-off. Twenty-eight 18- to 25-year-old adults kicked a playground ball at various percentages (50–100%) of their maximum speed at a wall target. Speed variability and spatial error were analyzed using repeated-measures ANOVA with built-in polynomial contrasts. Results indicated a significant inverse linear trajectory for speed variability (p < .001, η2= .345) where 50% and 60% maximum speed had significantly higher variability than the 100% condition. A significant quadratic fit was found for spatial error scores of mean radial error (p < .0001, η2 = .474) and subject-centroid radial error (p < .0001, η2 = .453). Findings suggest variability and accuracy of multijoint, ballistic skill performance may not follow the general principles of impulse-variability theory or the speed-accuracy trade-off.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

scholarly journals Viability of gait speed test in hospitalized elderly patients

2016 ◽  
Vol 42 (3) ◽  
pp. 196-202 ◽  
Author(s):  
Bruno Prata Martinez ◽  
Anne Karine Menezes Santos Batista ◽  
Isis Resende Ramos ◽  
Júlio Cesar Dantas ◽  
Isabela Barboza Gomes ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Gait Speed ◽  
Repeated Measures ◽  
Maximum Speed ◽  
Actual Performance ◽  
Physical Test ◽  
Speed Test ◽  
The Third ◽  
Hospitalized Elderly ◽  
Hospitalized Elderly Patients

ABSTRACT Objective: The gait speed test (GST) is a physical test that can predict falls and aid in the diagnosis of sarcopenia in the elderly. However, to our knowledge, there have been no studies evaluating its reproducibility in hospitalized elderly patients. The objective of this study was to evaluate the safety and reproducibility of the six-meter GST (6GST) in hospitalized elderly patients. Methods: This repeated measures study involved hospitalized elderly patients (≥ 60 years of age) who underwent the 6GST by the fifth day of hospitalization, were able to walk without assistance, and presented no signs of dyspnea or pain that would prevent them from performing the test. The 6GST was performed three times in sequence, with a rest period between each test, in a level corridor. Gait speed was measured in meters/second. Reproducibility was assessed by comparing the means, intraclass correlation coefficients (ICCs) and Bland-Altman plots. Results: We evaluated 110 elderly patients in a total of 330 tests. All participants completed all of the tests. The comparisons between the speeds obtained during the three tests showed high ICCs and a low mean bias (Bland-Altman plots). The correlation and accuracy were greatest when the mean maximum speed was compared with that obtained in the third test (1.26 ± 0.44 m/s vs. 1.22 ± 0.44 m/s; ICC = 0.99; p = 0.001; mean bias = 0.04; and limits of agreement = −0.27 to 0.15). Conclusions: The 6GST was proven to be safe and to have good reproducibility in this sample of hospitalized elderly patients. The third measurement seems to correspond to the maximum speed, since the first two measurements underestimated the actual performance.

Relationship between Speed and Accuracy in an over-Arm Throw

1984 ◽  
Vol 59 (1) ◽  
pp. 219-222 ◽  
Author(s):  
Catherine Indermill ◽  
William S. Husak
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Maximum Velocity ◽  
The Other ◽  
Spatial Accuracy ◽  
Fitts Law ◽  
Speed And Accuracy ◽  
Muscular Coordination

Principles of force and variability of force suggest that generating maximal forces will result in greater spatial accuracy. 18 right-handed males performed an over-arm throwing task at 50, 75, and 100% of maximum velocity while attempting to hit an archery target. A one-way analysis of variance of velocity with repeated measures on the target showed that the 75% condition was significantly more accurate than either of the other two. The principles may not be generalizable to tasks involving muscular coordination; it seems Fitts' Law may be more applicable.

scholarly journals Constructal model of fitts’s law to predict speed–accuracy trade-off

2017 ◽  
Vol 12 (1) ◽  
pp. 44-54
Author(s):  
Satish Boregowda ◽  
Rod Handy ◽  
Darrah Sleeth ◽  
Andrew Merryweather
Keyword(s):  
Trade Off ◽  
Speed Accuracy
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