Filtering by
- All Subjects: stroke
- All Subjects: Prosthesis
- Creators: Santello, Marco
- Creators: Honeycutt, Claire
- Creators: Schaefer, Sydney
- Status: Published
in space and time to meet different needs. Approximately 2 million Americans live
with an amputation with most of those amputations being of the lower limbs. To
advance current state-of-the-art lower limb prosthetic devices, it is necessary to adapt
performance at a level of intelligence seen in human walking. As such, this thesis
focuses on the mechanisms involved during human walking, while transitioning from
rigid to compliant surfaces such as from pavement to sand, grass or granular media.
Utilizing a unique tool, the Variable Stiffness Treadmill (VST), as the platform for
human walking, rigid to compliant surface transitions are simulated. The analysis of
muscular activation during the transition from rigid to different compliant surfaces
reveals specific anticipatory muscle activation that precedes stepping on a compliant
surface. There is also an indication of varying responses for different surface stiffness
levels. This response is observed across subjects. Results obtained are novel and
useful in establishing a framework for implementing control algorithm parameters to
improve powered ankle prosthesis. With this, it is possible for the prosthesis to adapt
to a new surface and therefore resulting in a more robust smart powered lower limb
prosthesis.
Methods such as vibratory sensory substitution have shown promise for providing prosthesis users with a sense of contact and have proved helpful in completing motor tasks. In this thesis, two experiments were conducted to determine whether vibratory cues could be useful in discriminating between sizes. In the first experiment, subjects were asked to grasp a series of hidden virtual blocks of varying sizes with vibrations on the fingertips as indication of contact and compare the size of consecutive boxes. Vibratory haptic feedback significantly increased the accuracy of size discrimination over objects with only visual indication of contact, though accuracy was not as great as for typical grasping tasks with physical blocks. In the second, subjects were asked to adjust their virtual finger position around a series of virtual boxes with vibratory feedback on the fingertips using either finger movement or EMG. It was found that EMG control allowed for significantly less accuracy in size discrimination, implying that, while proprioceptive feedback alone is not enough to determine size, direct kinesthetic information about finger position is still needed.
Does training in the upper extremity domain with startle translate to the speech domain post-stroke?
The aim of this study was to assess whether exposing individuals who are 6-month post-stroke with an upper extremity motor deficit and some form of speech impairment (aphasia and/or apraxia) to upper extremity training utilizing Startle Adjuvant Rehabilitation Therapy (START) would result in improvement in symptoms of speech impairment. It was hypothesized that while scores on Diadochokinetic Rate (a measure of apraxia) and Repetition (a measure of aphasia) would improve by timepoint with START as compared to the Control group, measures of aphasia including Spontaneous Speech, Auditory Verbal Comprehension, and Naming would not be different in scores by timepoint. Subjects were recruited from two separate ongoing studies consisting of three days of similar upper extremity training on certain functional tasks with and without START and the speech assessments utilized were pulled from the Western Aphasia Battery (Revised) and Apraxia Battery for Adults 2nd Edition. It was found that there were no statistically significant differences by timepoint in either condition for any of the speech assessments. This proof-of-concept study is the first to assess whether the StartReact effect, when applied to the upper extremity domain, will translate into measurable improvements in speech impairment despite the lack of any speech training.