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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 (down) 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
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Author Park, J.; Pazin, N.; Friedman, J.; Zatsiorsky, V.M.; Latash, M.L.
Title Mechanical properties of the human hand digits: Age-related differences Type Journal Article
Year 2014 Publication Clinical Biomechanics Abbreviated Journal
Volume (down) 29 Issue 2 Pages 129–137
Keywords hand; aging; friction; apparent stiffness; damping
Abstract Background

Mechanical properties of human digits may have significant implications for the hand function. We quantified several mechanical characteristics of individual digits in young and older adults.

Methods

Digit tip friction was measured at several normal force values using a method of induced relative motion between the digit tip and the object surface. A modified quick-release paradigm was used to estimate digit apparent stiffness, damping, and inertial parameters. The subjects grasped a vertical handle instrumented with force/moment sensors using a prismatic grasp with four digits; the handle was fixed to the table. Unexpectedly, one of the sensors yielded leading to a quick displacement of the corresponding digit. A second-order, linear model was used to fit the force/displacement data.

Findings

Friction of the digit pads was significantly lower in older adults. The apparent stiffness coefficient values were higher while the damping coefficients were lower in older adults leading to lower damping ratio. The damping ratio was above unity for most data in young adults and below unity for older adults. Quick release of a digit led to force changes in other digits of the hand, likely due to inertial hand properties. These phenomena of “mechanical enslaving” were smaller in older adults although no significant difference was found in the inertial parameter in the two groups.

Interpretations

The decreased friction and damping ratio present challenges for the control of everyday prehensile tasks. They may lead to excessive digit forces and low stability of the grasped object.
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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 0268-0033 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 73
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Author Krasovsky, T.; Keren-Capelovitch, T.; Friedman, J.; Weiss, P.L.
Title Self-feeding kinematics in an ecological setting: typically developing children and children with cerebral palsy Type Journal Article
Year 2021 Publication IEEE Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the IEEE Engineering in Medicine and Biology Society Abbreviated Journal IEEE Trans Neural Syst Rehabil Eng
Volume (down) 29 Issue Pages 1462-1469
Keywords
Abstract Assessment of self-feeding kinematics is seldom performed in an ecological setting. In preparation for development of an instrumented spoon for measurement of self-feeding in children with cerebral palsy (CP), the current work aimed to evaluate upper extremity kinematics of self-feeding in young children with typical development (TD) and a small, age-matched group of children with CP in a familiar setting, while eating with a spoon. METHODS: Sixty-five TD participants and six children diagnosed with spastic CP, aged 3-9 years, fed themselves while feeding was measured using miniature three-dimensional motion capture sensors (trakStar). Kinematic variables associated with different phases of self-feeding cycle (movement time, curvature, time to peak velocity and smoothness) were compared across age-groups in the TD sample and between TD children and those with CP. RESULTS: Significant between-age group differences were identified in movement times, time to peak velocity and curvature. Children with CP demonstrated slower, less smooth self-feeding movements, potentially related to activity limitations. CONCLUSIONS: The identified kinematic variables form a basis for implementation of self-feeding performance assessment in children of different ages, including those with CP, which can be deployed via an instrumented spoon.
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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 1534-4320 ISBN Medium
Area Expedition Conference
Notes PMID:34280104 Approved no
Call Number Serial 110
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Author Dempsey-Jones, H.; Wesselink, D.B.; Friedman, J.; Makin, T.R.
Title Organized Toe Maps in Extreme Foot Users Type Journal Article
Year 2019 Publication Cell Reports Abbreviated Journal Cell Reports
Volume (down) 28 Issue 11 Pages 2748-2756.e4
Keywords
Abstract Although the fine-grained features of topographic maps in the somatosensory cortex can be shaped by everyday experience, it is unknown whether behavior can support the expression of somatotopic maps where they do not typically occur. Unlike the fingers, represented in all primates, individuated toe maps have only been found in non-human primates. Using 1-mm resolution fMRI, we identify organized toe maps in two individuals born without either upper limb who use their feet to substitute missing hand function and even support their profession as foot artists. We demonstrate that the ordering and structure of the artists’ toe representation mimics typical hand representation. We further reveal “hand-like” features of activity patterns, not only in the foot area but also similarly in the missing hand area. We suggest humans may have an innate capacity for forming additional topographic maps that can be expressed with appropriate experience.
Address
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-1247 ISBN Medium
Area Expedition Conference
Notes doi: 10.1016/j.celrep.2019.08.027 Approved no
Call Number Serial 99
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Author Portnoy, S.; Rosenberg, L.; Alazraki, T.; Elyakim, E.; Friedman, J.
Title Differences in Muscle Activity Patterns and Graphical Product Quality in Children Copying and Tracing Activities on Horizontal or Vertical Surfaces Type Journal Article
Year 2015 Publication Journal of Electromyography and Kinesiology Abbreviated Journal Journal of Electromyography and Kinesiology
Volume (down) 25 Issue 3 Pages 540�547
Keywords Motor equivalence; Electromyography; Tablet; Occupational Therapy; Muscle fatigue; Motor control
Abstract The observation that a given task, e.g. producing a signature, looks similar when created by different motor commands and different muscles groups is known as motor equivalence. Relatively little data exists regarding the characteristics of motor equivalence in children. In this study, we compared the level of performance when performing a tracing task and copying figures in two common postures: while sitting at a desk and while standing in front of a wall, among preschool children. In addition, we compared muscle activity patterns in both postures. Specifically, we compared the movements of 35 five- to six-year old children, recording the same movements of copying figures and path tracing on an electronic tablet in both a horizontal orientation, while sitting, and a vertical orientation, while standing. Different muscle activation patterns were observed between the postures, however no significant difference in the performance level was found, providing evidence of motor equivalence at this young age. The study presents a straightforward method of assessing motor equivalence that can be extended to other stages of development as well as motor disorders.
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 1050-6411 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 77
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