Vibro-tactile Pressure Feedback of the Prosthetic Foot for Trans-tibial Amputees

Study Overview
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Brief Summary
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The aim of the study is to investigate the influence of a vibro-tactile device on trans-tibial amputees in terms of gait, pain and perception of the prosthesis.

Detailed Description
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The study is divided into three phases. The initial phase lasts 6 to 8 weeks for each subject. For subjects of group 2 the length of the initial phase depends on the progression of the re-innervation. The initial phase ends, when the subject can perceive the tactile stimulate at the re-innervated area of the skin. During the initial phase, all subjects get a new prosthesis. To minimize the adjusting to the new prosthesis only a new socket, which houses the vibro-tactile Feedback system, is fabricated and the old prosthetic food is re-used. After a period of 3 weeks minimum, where the subjects use the new prosthesis, a gait analysis and an assessment of the sensitivity of the skin at the stump are performed. Subsequently the intervention phase starts and the vibro-tactile feedback system is activated. For a period of 6 months the subjects use the new prostheses with the integrated vibro-tactile feedback system in daily living. After 2 and 4 months, the subjects visit the study site for an assessment of the sensitivity of the skin. After 6 months a second gait analysis and an other assessment of the sensitivity of the skin a the stump are performed. Afterwards the vibro-tactile feedback-system is disabled. During the observing phase the subjects use the prosthesis with the disabled vibro-tactile feedback system for 4 months. During all three phases the subjects answer the questionnaires every 2 months.

Official Title
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Vibro-tactile Pressure Feedback of the Prosthetic Foot for Trans-tibial Amputees

Conditions
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Amputation

Intervention / Treatment
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* Device: Vibro-tactile Feedback


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: unilateral trans-tibial amputation uses a prostheses already for more than 1 year sufficient touch sensitivity at the stump unimpaired contralateral lower extremity Exclusion Criteria: psychiatric disorder cognitive restrictions pregnant or breast feeding women

Ages Eligible for Study
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Minimum Age: 18 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Trans-tibial Amputees<br>Unilateral Trans-tibial Amputees that use vibro-tactile feedback for six months in daily living | Device: Vibro-tactile Feedback<br>* The device measures the force between the prosthetic food and the ground. With this signals, vibratators are triggered. The vibrators are housed by the prosthetic socket and stimulate the stump.<br>|
| Experimental: Trans-tibial Amputees with TSR<br>Unilateral Trans-tibial Amputees that use vibro-tactile feedback for six months in daily living. The subjects underwent a functional nerv-transfer surgery prior to participation, where the proximal part of the sural nerv was to the distal part of the saphenous nerv. | Device: Vibro-tactile Feedback<br>* The device measures the force between the prosthetic food and the ground. With this signals, vibratators are triggered. The vibrators are housed by the prosthetic socket and stimulate the stump.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R) | The Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R) is a multidimensional instrument designed to examine the psychosocial processes involved in adjusting to amputation and a prosthesis. TAPES consists of 9 subscales, with possible scores depending on the single subscale. The range is from 0-12 to 0-25 (depending on the number of items and answer possibilities). | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fall Efficacy Scale International Version (FES-I) | The Fall Efficacy Scale International Version (FES-I) is a questionaire that assesses the fear of falling. Scores can range from 16-64, with a higher score indicating a higher fear of falling. | 1 year | 
| Pain Visual analoge scale (VAS) | The pain is measured with a Visual analoge scale form 0 to 10. O indicates no pain, while 10 is the worst pain the person can imagine. | 1 year | 
| Number of falls within the last two months | Subjects report the number a falls within the last two months. | 1 Year | 
| Gait parameters | Two gait analysis are performed with a 3D video-based marker system. Standard gait parameters (as cardence, speed, step length and weight) as well as kinematic and kinetic parameters are calculated. | 6 months | 
| two point discrimination | the two point discrimination (in mm) at the skin of the stump is assessed | 6 months | 
| touch perception threshold | the touch percertion at the skin of the stump is assessed with mono filaments | 6 months |