Comparative Effectiveness of Microprocessor Controlled and Carbon Fiber Prosthetic Feet in Transtibial Amputees

Study Overview
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Brief Summary
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The purpose of this research is to evaluate benefits of a microprocessor controlled prosthetic ankle-foot device compared to a non-microprocessor controlled or passive carbon fiber prosthetic ankle-foot device.

Detailed Description
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Recent advancements in microprocessor controlled prosthetic ankle-foot systems have allowed additional functionality for the lower limb amputee, but research into the effectiveness of microprocessor controlled ankle-foot systems has been limited. In this research study, differences in perceived mobility, functional capabilities and gait parameters between energy storing and returning and microprocessor controlled ankle-foot mechanisms will be identified where they exist. Also a comparison of the initial function with a new system compared to the function after a four week accommodation period will provide insight into the time it takes for the prosthesis user to experience a benefit from a microprocessor ankle-foot.

Official Title
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Comparative Effectiveness of Microprocessor Controlled and Carbon Fiber Energy Storing and Returning Prosthetic Feet in Persons With Unilateral Transtibial Amputation

Conditions
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Amputation

Intervention / Treatment
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* Device: Kinnex
* Device: Pacifica LP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Unilateral transtibial amputation Age 18-99 years old Body weight below 275 lbs Non-pregnant English speaking Current user of prosthesis for at least one year Wear time 8 hrs/day or more MFCL ≥ K-3 Well-fitting and functioning prosthesis No use of ambulatory aide Able to tolerate testing protocol Able to walk on slopes Must, in the opinion of the investigator, be willing and able to complete all aspects of the study, adhere to the study visit schedule and comply with the assessments Exclusion Criteria: Amputation level other than unilateral transtibial Age <18 or >99 years old Body weight above 275 lbs Pregnant Non-English speaking Not current user of prosthesis Less than one year use of prosthesis Wear time less than 8 hr/day MFCL <K3 Poor fitting and functioning prosthesis Indicating that the socket fit is painful, or unacceptable Use of ambulatory aide Unable to tolerate testing protocol Unable to walk on slopes Presence or history of any condition that, in the view of the investigator, places the participant at high risk of poor treatment compliance or of not completing the study Any neurologic impairments known to cause gait and/or balance dysfunction

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Configuration A (Kinnex)<br> | Device: Kinnex<br>* The Kinnex is a microprocessor controlled hydraulic ankle foot device (Freedom Innovations, Irvine, CA).<br>|
| Active Comparator: Configuration B (Pacifica LP)<br> | Device: Pacifica LP<br>* The Pacifica LP is a carbon-fiber ankle foot device (Freedom Innovations, Irvine, CA)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amputee Mobility Predictor with Prosthesis (AMPPRO) | The AMPPRO is a functional test consisting of 21 tasks that are similar to everyday function to test balance, strength and walking ability | Collection at baseline | 
| L-Functional Test (L-Test) Baseline | The L-test is a timed functional test that involves standing from a chair, walking 3 meters, turning around and sitting back into the chair. | Collection at baseline | 
| 5 times Sit-to-Stand (5 times STS) Baseline | The 5 times STS is a timed functional test that measures how long it takes to stand and sit five times in a row from a chair. | Collection at baseline | 
| 6 minute Timed Walk Test (6m TWT) Baseline | The 6m TWT involves walking as far as possible along a straight path between two cones in under 6 minutes. | Collection at baseline | 
| Physiological Cost Index (PCI) Baseline | The PCI is calculated by subtracting resting heart rate from active heart rate following a walking test, and dividing the difference by the walking speed. | Collection at baseline | 
| Hill Assessment Index (HAI) Baseline | The HAI is a functional test that measures quality of walking up and down a sloped ramp. | Collection at baseline | 
| 2 Dimensional Video Motion Analysis (2D Video Analysis) Baseline | 2D Video Analysis will be used to measure knee and ankle angles at mid-stance of gait while walking up and down the sloped ramp and also while standing still on level ground. | Collection at baseline | 
| L-Functional Test (L-Test) after 4 weeks | The L-test is a timed functional test that involves standing from a chair, walking 3 meters, turning around and sitting back into the chair. | Collection after 4 weeks | 
| 5 times Sit-to-Stand (5 times STS) after 4 weeks | The 5 times STS is a timed functional test that measures how long it takes to stand and sit five times in a row from a chair. | Collection after 4 weeks | 
| 6 minute Timed Walk Test (6m TWT) after 4 weeks | The 6m TWT involves walking as far as possible along a straight path between two cones in under 6 minutes. | Collection after 4 weeks | 
| Physiological Cost Index (PCI) after 4 weeks | The PCI is calculated by subtracting resting heart rate from active heart rate following a walking test, and dividing the difference by the walking speed. | Collection after 4 weeks | 
| Hill Assessment Index (HAI) after 4 weeks | The HAI is a functional test that measures quality of walking up and down a sloped ramp. | Collection after 4 weeks | 
| 2 Dimensional Video Motion Analysis (2D Video Analysis) after 4 weeks | 2D Video Analysis will be used to measure knee and ankle angles at mid-stance of gait while walking up and down the sloped ramp and also while standing still on level ground. | Collection after 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Orthotic Prosthetic User Survey (OPUS) | The OPUS is a self-reported questionnaire that asks about satisfaction with device | Collection after 4 weeks | 
| Prosthesis Evaluation Questionnaire - Mobility Subscale (PEQ-MS) | The PEQ-MS is a self-reported questionnaire that measures perceived difficulty ambulating on a variety of environmental barriers | Collection after 4 weeks | 
| Prosthesis Limb User Survey of Mobility (PLUS-M) | The PLUS-M is a self-reported questionnaire that measures perceived mobility with a prosthesis in different environments. | Collection after 4 weeks | 
| Activities-Specific Balance Confidence Scale (ABC) | The ABC is a self-reported questionnaire that measures confidence in balance while performing various activities in different environments. | Collection after 4 weeks | 
| Socket Comfort Score (SCS) | The SCS is a self-reported questionnaire that asks the participant to rate their current socket comfort from 0-10, with 10 points representing the most comfortable socket they can imagine. | Collection at baseline and after 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Microprocessor Controlled Ankle, Transtibial Amputee, Pacifica LP, Kinnex