| Records |
| Author |
Friedman, Jason; Flash, Tamar |
| Title |
Task-dependent selection of grasp kinematics and stiffness in human object manipulation |
Type |
Journal Article |
| Year |
2007 |
Publication |
Cortex |
Abbreviated Journal |
|
| Volume |
43 |
Issue |
3 |
Pages  |
444-460 |
| Keywords |
|
| Abstract |
Object manipulation with the hand is a complex task. The task has redundancies at many levels, allowing many possibilities for the selection of grasp points, the orientation and posture of the hand, the forces to be applied at each fingertip and the impedance properties of the hand. Despite this inherent complexity, humans perform object manipulation nearly effortlessly. This article presents experimental findings of how humans grasp and manipulate objects, and examines the compatibility of grasps selected for specific tasks. This is accomplished by looking at the velocity transmission and force transmission ellipsoids, which represent the transmission ratios of the corresponding quantity from the joints to the object, as well as the stiffness ellipsoid which represents the directional stiffness of the grasp. These ellipsoids allow visualization of the grasp Jacobian and grasp stiffness matrices. The results show that the orientation of the ellipsoids can be related to salient task requirements. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Penn State @ write.to.jason @ |
Serial |
14 |
| Permanent link to this record |
| |
|
| |
| Author |
Melzer, I.; Liebermann, D.G.; Krasovsky, T.; Oddsson, L.I.E. |
| Title |
Cognitive load affects lower limb force-time relations during voluntary rapid stepping in healthy old and young adults |
Type |
Journal Article |
| Year |
2010 |
Publication |
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences |
Abbreviated Journal |
J Gerontol A Biol Sci Med Sci |
| Volume |
65 |
Issue |
4 |
Pages |
400-406 |
| Keywords |
*Accidental Falls; Adult; Aged; Aged, 80 and over; Aging/*physiology; Attention/physiology; Cognition/*physiology; Gait/*physiology; Humans; Postural Balance/*physiology; Reaction Time |
| Abstract |
BACKGROUND: Quick step execution may prevent falls when balance is lost; adding a concurrent task delays this function. We investigate whether push-off force-time relations during the execution of rapid voluntary stepping is affected by a secondary task in older and young adults. METHODS: Nineteen healthy older adults and 12 young adults performed rapid voluntary stepping under single- and dual-task conditions. Peak power, peak force, and time to peak force during preparatory and swing phases of stepping were extracted from center of pressure and ground reaction force data. RESULTS: For dual-task condition compared with single-task condition, older adults show a longer time to reach peak force during the preparation and swing phases compared with young adults (approximately 25% vs approximately 10%, respectively). Peak power and peak force were not affected by a concurrent attention-demanding task. CONCLUSION: Older adults have difficulty allocating sufficient attention for fast muscle recruitment when concurrently challenged by an attention-demanding task. |
| Address |
Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1079-5006 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:19939911 |
Approved |
no |
| Call Number |
|
Serial |
50 |
| Permanent link to this record |
| |
|
| |
| Author |
Goodman, D.; Liebermann, D.G. |
| Title |
Time-to-contact as a determiner of action: vision and motor control |
Type |
Book Chapter |
| Year |
1992 |
Publication |
Vision and Motor Control |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
335-349 |
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Elsevier Pub. Co |
Place of Publication |
Amsterdam, Holland |
Editor |
D. Elliott; J. Proteau |
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
43 |
| Permanent link to this record |
| |
|
| |
| Author |
Tenenbaum, G.; Kohler, N.; Shraga, S.; Liebermann, D.G.; Lidor, R. |
| Title |
Anticipation and confidence of decisions related to skilled performance |
Type |
Journal Article |
| Year |
1996 |
Publication |
Journal of Sport Psychology |
Abbreviated Journal |
|
| Volume |
27 |
Issue |
|
Pages |
293-307 |
| Keywords |
|
| Abstract |
This study was carried out to examine anticipatory decisions of novice, intermediate, and expert tennis players and the confidence with which these decisions are made by these athletes. Perceived eye-focus was also measured to verify whether it is related to expertise level prior to action execution. Forty-five Australian players, 15 in each skill category, were exposed to 6 temporal occluded film conditions (480, 320, 160 ms prior to racquet-ball contact, at contact, and 160 and 320 ms after contact) in randomized order within 8 tennis strokes. In each condition, after viewing the filmed sequence, they were asked to report the final ball location of the opponent's stroke, how confident they were in this decision, and their perceived eye-focus location during the sequence. Experts and intermediates were superior in anticipatory decisions to their counterparts, only under short exposure durations. Novices showed more confidence than experts and intermediates at the beginning of the sequence, but after 160 and 320 ms of ball-racquet contact, experts were much more confident than novices, and intermediates. Self-reported eye-focus differed substantially with respect to expertise level. While experts attended to several locations prior to ball-racquet contact, intermediate and novice players gazed at one location. After contact, the reverse was evident. The findings are in partial agreement with other studies which have applied the temporal occlusion paradigm to study expert-novice differences in anticipatory skills. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
59 |
| Permanent link to this record |
| |
|
| |
| Author |
Raveh, E.; Friedman, J.; Portnoy, S. |
| Title |
Visuomotor behaviors and performance in a dual-task paradigm with and without vibrotactile feedback when using a myoelectric controlled hand |
Type |
Journal Article |
| Year |
2018 |
Publication |
Assistive Technology |
Abbreviated Journal |
Assistive Technology |
| Volume |
30 |
Issue |
|
Pages |
274-280 |
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1040-0435 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
85 |
| Permanent link to this record |
