Photograph of the DEKA GEN 3 arm courtesy of Stewart Coulter.
In May, the U.S. Food and Drug Administration (FDA) announced that it allows marketing of the “Luke Skywalker” DEKA Arm System, DEKA Integrated Solutions, Manchester, New Hampshire. Now, a new study, published in Volume 51, Number 3 of the Journal of Rehabilitation Research & Development, examines self-reported and performance-based outcomes using the DEKA Arm System, DEKA Integrated Solutions, Manchester, New Hampshire.
Mechanical properties of the DEKA Arm and associated engineering innovations are easy to observe. What is less clear is how these advances translate into functional benefits for the user. This quasi-experimental study aimed to quantify outcomes including dexterity, performance of daily activities, and prosthetic skill and spontaneity of users of the DEKA Arm and also to compare outcomes when using the DEKA Arm with scores using their existing prosthesis. This study was conducted as part of the overall U.S. Department of Veterans Affairs (VA) study to optimize the DEKA Arm.
Of the 39 subjects fit with a DEKA Arm: 12 with a radial configuration (RC), 13 with a humeral configuration (HC), and 14 with a shoulder configuration (SC); 32 were trained in its use and completed end-of-study testing. (Of the seven who terminated early, six used the HC and one the RC.) A comparison of outcome measures using their existing device with outcome measures using the DEKA Arm was made for 26 individuals who completed the study.
Outcome measures were administered at the first study visit and again one week later using the subject’s existing prosthesis, re-administered at the onset of training with the DEKA Arm, and after every five training visits until the end of the study. Subjects in this study used various types of upper-limb devices: some myoelectric, some body-powered, and others hybrid. A variety of terminal devices were used, including standard hooks and various myoelectric hands. Outcome measures of activity performance included four performance-based measures: the Modified Box and Block Test of Manual Dexterity (BB), the Jebsen-Taylor Hand Function Test (JTHF), the Activities Measure for Upper-Limb Amputees (AM-ULA), the University of New Brunswick Test of Prosthetic Function for Unilateral Amputees (UNB); and two self-report measures: the Upper-Extremity Functional Scale (UEFS) from the Orthotics and Prosthetics Users Survey and the Patient-Specific Functional Scale (PSFS). All performance-based measures were administered by occupational therapists.
The study found that although dexterity varied by amputation level, self-reported function, and number of activities performed using the prosthesis were similar across amputation levels. Comparisons of the DEKA Arm with existing prostheses showed that the effect of the DEKA Arm on dexterity was equivalent or mixed. Activity performance and spontaneity of prosthetic use improved for SC users, whereas use of the prosthesis to perform activities and perceived difficulty in performing self-selected tasks improved for participants of all levels of amputation using the DEKA Arm.
