Matching Items (3)
Description
The development of advanced, anthropomorphic artificial hands aims to provide upper extremity amputees with improved functionality for activities of daily living. However, many state-of-the-art hands have a large number of degrees of freedom that can be challenging to control in an intuitive manner. Automated grip responses could be built into artificial hands in order to enhance grasp stability and reduce the cognitive burden on the user. To this end, three studies were conducted to understand how human hands respond, passively and actively, to unexpected perturbations of a grasped object along and about different axes relative to the hand. The first study investigated the effect of magnitude, direction, and axis of rotation on precision grip responses to unexpected rotational perturbations of a grasped object. A robust "catch-up response" (a rapid, pulse-like increase in grip force rate previously reported only for translational perturbations) was observed whose strength scaled with the axis of rotation. Using two haptic robots, we then investigated the effects of grip surface friction, axis, and direction of perturbation on precision grip responses for unexpected translational and rotational perturbations for three different hand-centric axes. A robust catch-up response was observed for all axes and directions for both translational and rotational perturbations. Grip surface friction had no effect on the stereotypical catch-up response. Finally, we characterized the passive properties of the precision grip-object system via robot-imposed impulse perturbations. The hand-centric axis associated with the greatest translational stiffness was different than that for rotational stiffness. This work expands our understanding of the passive and active features of precision grip, a hallmark of human dexterous manipulation. Biological insights such as these could be used to enhance the functionality of artificial hands and the quality of life for upper extremity amputees.
ContributorsDe Gregorio, Michael (Author) / Santos, Veronica J. (Thesis advisor) / Artemiadis, Panagiotis K. (Committee member) / Santello, Marco (Committee member) / Sugar, Thomas (Committee member) / Helms Tillery, Stephen I. (Committee member) / Arizona State University (Publisher)
Created2013
Description
The aim of this study is to understand the affects of grip strength and manual dexterity in activities of daily living (ADL) in persons with Down syndrome (DS). This is important because it could help with future interventions that are focused around improving related disadvantages in this particular population. Ten participants with DS performed the manual dexterity tests (i.e., Purdue Pegboard) and measured their grip strength with a hydraulic dynamometer. Overall, grip strength was lower than the average for the typical population and was reduced after aeorbic exercise. Improvements, however, were found in their manual dexterity from pre-test to post-test. This indicates that the assisted moderate intensity exercise intervention helped their dexterity performance. The improvements in dexterity are consistent with previous research conducted by Ringenbach et al. (2007). These results suggest that a moderate intensity treadmill walking exercise intervention can increase precision and efficiency in dexterity in persons with Down syndrome, however their grip force production may be stimulated by another means.
ContributorsSemper, Logan (Author) / Ringenbach, Shannon (Thesis director) / Kulinna, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2012-12
Description
The primary goal of this study is to assess and develop an understanding of the effects of Assisted Cycling Therapy on manual motor performance in children with Down syndrome. Seven children (Mage 11.6 years old) completed a 30-minute cycle session 2x/week for 8 weeks on the PACT bicycle at a 35% greater rate than their self-selected rate. Pre- and post-testing of grip force with a dynamometer and unimanual and bimanual manual dexterity using the Purdue Pegboard were measured to determine changes in force production and fine motor control, respectively. Results consistently showed improvements in grip force in both hands and bimanual dexterity following PACT. My results are interpreted with respect to cerebral lateralization and neuroplasticity following PACT intervention.
ContributorsGunther, Bryn (Author) / Ringenbach, Shannon (Thesis director) / Ofori, Edward (Committee member) / Rand, Miya (Committee member) / Rafie, Fourozan (Committee member) / Barrett, The Honors College (Contributor) / College of Health Solutions (Contributor)
Created2023-05