Comparison of Prosthetic Feet for People With Syme's Amputation (XF Symes Study)

Functional Assessment of High-profile Crossover Feet in People With Syme's Amputation

The purpose of this study is to compare the functional differences between two types of foot prostheses for people with ankle disarticulation (Syme's) amputations. The two feet being tested are low- and high-profile feet, with the difference being the latter has an extended keel and attaches to the posterior of the prosthetic socket, rather than the distal end. The hypothesis is that the high-profile foot (i.e., the crossover foot) will lead to functional and biomechanical improvements compared to low-profile feet.

Study Overview

• Status: Completed
• Conditions: Amputation; Artificial Limb
• Intervention / Treatment: Device: Crossover foot; Device: Energy Storing Foot

Detailed Description

Syme's prostheses are typically limited to low-profile prosthetic feet due to clearance restrictions below the prosthetic socket. As a result, the functional benefits provided by the long residual limb are mitigated by prosthetic design limitations. Recently, high-profile, posteriorly-attaching crossover feet have been modified for use with people who have Syme's amputation. Crossover feet theoretically improve motion and energy storage-and-return compared to traditional foot options for the Syme's level. Crossover feet also have the potential to broaden the range of high-impact activities that can be performed with a single prosthesis. However, to date there is no empirical evidence that compares functional differences when walking with high-profile crossover feet compared to low-profile feet for people with Syme's amputation. This mixed-method pilot research will use a randomized, controlled within-participants design. Investigators will assess gait biomechanics, self-reported health outcomes, and qualitative interviews to compare relative advantages and disadvantages of traditional low-profile Syme's feet and high-profile crossover feet. This proposed work will create a foundation for future research that examines the potential benefits of crossover feet in people with Syme's amputation. In addition, results from this research will be used clinically to inform prosthetic options for people with limited clearance for distally-attached prosthetic feet.

• Study Type: Interventional
• Enrollment (Actual): 5
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98195
      • University of Washington, Amplifying Mobility and Performance Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 18 years of age or older
• Have a unilateral Syme's amputation that occurred >1 year prior
• Owns a crossover foot modified for Syme's use
• Able to walk in the community without assistance
• Able to read and write in English

Exclusion Criteria:

• Have other amputations
• Have a health condition that would limit completion of the study protocol (e.g., skin breakdown, heart disease)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Foot 1: Crossover Foot, Foot 2: Energy Storing Foot; Participant randomized to crossover foot as first condition, energy storing foot as second condition	Device: Crossover foot; A prosthetic foot that features an extended strut (keel) that attaches to the posterior proximal aspect of the prosthetic socket.; Device: Energy Storing Foot; A prosthetic foot that features a short strut (keel) that attaches to the distal aspect of the prosthetic socket.
Experimental: Foot 1: Energy Storing Foot, Foot 2: Crossover Foot; Participant randomized to energy storing foot as first condition, crossover foot as second condition	Device: Crossover foot; A prosthetic foot that features an extended strut (keel) that attaches to the posterior proximal aspect of the prosthetic socket.; Device: Energy Storing Foot; A prosthetic foot that features a short strut (keel) that attaches to the distal aspect of the prosthetic socket.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratio Between Sound and Prosthetic Side Step Lengths	The symmetry between prosthetic and sound side step lengths. Step lengths were calculated as the distance between heels from heel strike of the contralateral foot to heel strike of the ipsilateral foot.	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)
Total Prosthetic Ankle Range of Motion	The change in total angular motion of the ankle in the sagittal plane (e.g., dorsiflexion & plantarflexion) during stance phase between prosthetic feet, in degrees	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)
Prosthetic-side Energy Return	Intersegmental flow of power out of the prosthesis	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)
Peak Sound-side Limb Loading	Maximum vertical ground reaction force in early stance	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Preference Questionnaire	At the end of the study, participants will engage in a preference questionnaire with open-ended follow-up questions to elicit preferences and experiences with both feet. Questions will ask about overall preference, and preference for a range of mobility activities (e.g., "Which foot did you prefer overall, and why?" and "Which foot did you prefer for walking up stairs, and why?").	Session 4 (after 4 weeks of prosthesis wear, 2 weeks of prosthesis 1 and 2 weeks of prosthesis 2)
Change in Prosthetic Limb Users Survey of Mobility (PLUS-M) 12-item Short Form Version 1.2	Self-reported measure of mobility, the PLUS-M 12-item Short Form is a single measure, scores range from 17.5-76.6, higher scores represent better mobility.	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)
Change in Activities-Specific Balance Confidence Scale (ABC)	Self-reported measure of balance confidence, the ABC is a single measure, scores range from 0-4, higher scores represent better balance confidence.	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)
Change in Trinity Amputation and Prosthesis Experience Scales- Revised Aesthetic Satisfaction	Self-reported measures of aesthetic prosthetic satisfaction, scores on items are averaged and range from 0-2, higher values represent more satisfaction (better outcome)	Sessions 3 (after 2 weeks of prosthesis 1 wear) and 4 (after 2 weeks of prosthesis 2 wear)

Collaborators and Investigators

• Sponsor: University of Washington
• Investigators: Principal Investigator: Sara Morgan, PhD, CPO, University of Washington

Study record dates

Study Major Dates

• Study Start (Actual): July 22, 2019
• Primary Completion (Actual): December 3, 2019
• Study Completion (Actual): December 3, 2019

Study Registration Dates

• First Submitted: August 16, 2019
• First Submitted That Met QC Criteria: September 9, 2019
• First Posted (Actual): September 11, 2019

Study Record Updates

• Last Update Posted (Actual): December 14, 2020
• Last Update Submitted That Met QC Criteria: November 17, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Keywords: Prosthesis; Biomechanics; Amputation; Ankle disarticulation; Syme; Prosthetic foot; Crossover foot
• Other Study ID Numbers: STUDY00007788

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No