Date Presented 04/06/19
There are a limited number of body-powered prosthetics available for partial thumb amputates. The loss of thumb function affects operations such as manipulation and pinch. The MCPThumb is a body-powered thumb prosthetic that allows individuals with a partial thumb amputation to regain function and confidence during everyday tasks. Results from this study indicated that the participant performed to a higher functional level while utilizing the MCPThumb.
Primary Author and Speaker: Susan Denham
Additional Authors and Speakers: Ethan Powell
Contributing Authors: Jinha Jeong, Ashley Langford, Anna Moore
PURPOSE: The purpose of this study was to examine the functionality of the Body Powered Metacarpal-Phalangeal Thumb (MCPThumb).
BACKGROUND: The MCPThumb was developed by Naked Prosthetics and is the first body-powered prosthetics for individuals with partial thumb amputations. It is driven by at least a 3/8 residual proximal phalanx of the thumb. This prosthetic is in early production and the subject of this study was the first person fitted with the device. The MCPThumb consists of durable components such as a titanium frame, and a heavy-duty rubber tip and straps. These components allow the MCPThumb withstand dirty and wet environments without malfunctioning.
DESIGN/DATA SOURCE/METHODS: The research design was a single case study. The participant was the first client to be fitted with this prosthetic device. Th researches used a mixed method of qualitatitve and quantitative assessments. They administered various standardized and non-standardized tests to a single participant to examine how the MCPThumb performed in comparison to the affected hand without the MCPThumb. The following standardized assessments were administered: Minnesota Manual Dexterity Test, Purdue Pegboard Test, and Jebsen-Taylor Hand Functioning Test. The Disabilities of the Arm, Shoulder, and Hand (DASH) functional outcome measure, a functional activity assessment, and a client-centered questionnaire developed by the researchers were also administered to examine the participant’s ability to perform various functional activities.
RESULTS: The results were analyzed to show the percent change between the administered standardized assessments and a statistical analysis was performed to see if there was a statistical significant change where p ≤ 0.05.
CONCLUSION: When wearing the MCPThumb, the participants hand function showed an increasing trend in every subtest on the Minnesota Manual Dexterity Test and in every subtest on the Jebson-Taylor Hand Functioning Test except the writing and stacking checkers. The participant self-rated his functional level for both work and everyday task using the DASH. The participant demonstrated an increase in function on both of these outcomes by 40% for everyday tasks and 58% for work related tasks. In addition to self-rating function, the participant self-rated his confidence level while using the MCPThumb. Upon analyzing the participant responses, the researches found that the participant’s confidence level increased while performing every day tasks and work related tasks.
IMPACT RELATED TO RESEARCH: The results indicated that the participant performed to a higher functional level and demonstrates improved confidence while utilizing the Body-Powered MCPThumb prosthetic device on his affected hand. This indicates that the MCPThumb is a viable option for individuals who sustain a partial thumb amputation. This research serves as the first step in additional studies to build the literature discussing this type of prosthetic option for thumb amputees.
References
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