This research and development will improve upon and investigate the potential validity of an innovative new transradial socket and harness design (the KSH system) that offers an alternative to standard hard sockets and rubber liners with a hybrid polymer and textile-based design derived from advanced athletic shoe technology. The project consists of designing, custom fitting and evaluating the function and comfort of the this new novel system. The study will take place in 3 phases; Phase 1, five experienced Veterans with transradial arm amputations will be recruited to provide guidance and to assist with the design and development. Experienced end-user Veterans and Clinical staff will work together to assist with design, develop the fitting process and working with engineers on the design of a completely digital fitting device for measuring the residual limb and locating bony prominences of the limb to inform the socket design. Phase 2, testing and assessment, the design and process validation will take place with the five Veteran upper transradial arm amputees Phase 3, an additional 20 Veterans with transradial arm amputations will be recruited and fit with the KSH system and undergo a series of evaluative tests. Veterans will perform a series of static and dynamic tasks to evaluate function, comfort and load bearing failure. The primary goal of this study is to improve upon the current preliminary prototype and to test it with a broader population of potential users to help advance the engineering and design, and to learn the potential to fit a range of Veterans with transradial amputations.
Unilateral transradial arm amputation
Possession of a functioning and wearable previously fit prosthetic arm of any type
Residual limb length of at least 4 inches from the lateral epicondyle to the distal tip
Residual limb length less than or equal to that allowing a clearance of 1.5 inches from a fitted wrist
Current open sores or incisions, Heterotopic ossification (HO), traumatic neuromas, or any other condition preventing the wearing of a prosthetic socket
Residual limb length less than 4 inches
Residual limb length greater than that allowing 1.5 inches clearance from a fitted wrist.
Crossover
K-Socket-Harness
DeviceA transradial socket and harness design that offers a hybrid polymer and textile-based design derived from advanced athletic shoe technology. The KSH integrated socket, frame, and wrist, the "variable compliance prosthetic socket with breathable matrix," creates a dynamic and secure attachment with a combination of two lacing systems. The lacing systems lengthen and shorten six flexible hinges at the elbow, maintaining a secure attachment throughout the range of motion and accounting for volume changes in the soft tissue of the elbow that would otherwise restrict range of motion or cause the socket to separate from the residual limb.
Static tensile load bearing capacity to reach a 50-pound load on an industrial scale
The investigators will test tensile static load bearing capacity up to a 50 -pound load or to failure. The Veteran will stand safely on an industrial scale with the arm extended at their side and weight will be added to the distal end of the prosthesis until the goal is met or the prosthesis fails. The investigators will perform the task on both the KSH socket and the standard socket.
Elbow range of motion in flexion/extension
The investigators will measure range of motion (in degrees) in flexion/extension with a standard goniometer. The investigators will perform the task on both the KSH socket and the standard socket.
Donning/doffing prosthesis
The investigators will record the time it takes to donn/doff each prosthesis for both the KSH socket and the standard socket.
Power in Watts generated on rowing machine
The investigators will test tensile loads in a dynamic environment before failure. The investigators will test the performance on a rowing ergometer 10-minute test before failure, as measured using power in Watts. The investigators will perform the task on both the KSH socket and the standard socket.
Usability of prosthesis using the System Usability Score (SUS) on scale from 0-100
Participants will report usability with setup and operation of the device from ten questions using a five point Likert scale. The higher the score, the more usable (user friendly) the device is rated by the Veteran. The investigators would like the KSH system to score \>80 on the System Usability Scale (SUS)).
Socket Comfort Scores (SCS) on a scale from 0-10
Participants will report Socket Comfort Scores (SCS) after wearing and testing of the devices for both with the KSH and current standard-of-care prosthesis by using an 11 point scale, (0-10) zero being the most uncomfortable socket fit you can image, and 10 being the most comfortable socket fit.
Weight of device in pounds
The investigators will correlate the weight of the prosthesis in pounds with user satisfaction of both the KSH device and the participants' current device.
Participant preference
The investigators will ask the participant which device design they prefer to use.
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VA Office of Research and Development
Lead sponsor
Stumpworx LLC
Collaborator
