Prosthetic Performance Enhancement Trial (PROSPER)

The purpose of this research is to determine the feasibility of an uneven terrain walking program for lower limb prosthesis users. The training is designed to induce step-to-step variability during walking within a safe environment, with the aim of improving walking skill and confidence.

Study Overview

• Status: Recruiting
• Conditions: Lower Limb Amputation Below Knee (Injury); Lower Limb Amputation Above Knee (Injury); Amputation; Lower Limb Amputation Knee; Lower Limb Amputation at Ankle (Injury); Lower Limb Amputation at Hip (Injury)
• Intervention / Treatment: Other: Flat terrain locomotor training; Other: Uneven terrain locomotor training

Detailed Description

Despite advances in the technology for artificial limbs (prostheses), falling and the fear of falling continue to be barriers to mobility for many lower limb prosthesis users after their initial rehabilitation. The loss of ability and confidence in pursuing everyday tasks negatively impacts quality of life, and ongoing physical and mental health. This study will test and improve a rehabilitation training intervention involving walking on uneven ground to improve walking skill and confidence in lower limb prosthesis users.

Lower limb prosthesis users will be recruited. Participants will be allocated randomly to receive either intervention A: training on a flat surface, or intervention B: training on an uneven surface. Depending on their ability and confidence, participants will complete the walking practice either on a treadmill or on a mat with an identical surface pattern. The walking practice will take place three times per week for four weeks. As each participant improves their ability, training tasks will be made more difficult by limiting handrail use, by increasing walking speed, and, for intervention B, also by making the walking surface more uneven.

The objectives of this pilot study are to evaluate adherence and refine the training protocols in preparation for a definitive trial that will inform rehabilitation practices.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jenny A Kent, PhD, CSci; Phone Number: 7028955949; Email: jenny.kent@unlv.edu

Study Locations

• United States
  • Nevada
    • Las Vegas, Nevada, United States, 89154
      • Recruiting
      • University of Nevada Las Vegas
      • Contact: Jenny A Kent, PhD, CSci; Phone Number: 7028955949; Email: jenny.kent@unlv.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• lower limb amputation at ankle (Symes) level and above
• age 18+ years
• fitted with a walking prosthesis and use it regularly for home and/or community ambulation
• good socket fit, assessed by a score of 8-10 on the socket fit comfort scale
• able to walk for three minutes at a time with or without an assistive device

Exclusion Criteria:

• leg/foot ulcer or other conditions that cause pain during weight-bearing
• poor skin integrity that could cause tissue breakdown by walking
• cardiovascular, respiratory or other critical health conditions that preclude moderate physical activity
• unilateral or bilateral upper limb absence or loss at the wrist and above that precludes use of handrails bilaterally, or would require asymmetrical adaptation to body posture for use.
• pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Flat terrain training; Walking on a standard, flat treadmill or mat.	Other: Flat terrain locomotor training; The training will be comprised of up to 12 sets of 2-min continuous walking on a level treadmill or mat, interspersed with rest breaks of at least one minute. Training will be completed three times per week for four weeks.
Experimental: Uneven terrain training; Walking on an uneven terrain treadmill or mat.	Other: Uneven terrain locomotor training; The training will be comprised of up to 12 sets of 2-min continuous walking on an uneven terrain treadmill or mat, interspersed with rest breaks of at least one minute. Training will be completed three times per week for four weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Session adherence	Percentage of planned sessions attended, per participant.	Through study completion, over 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
L-test time	Time to complete L-test, in s. Participant rises from a chair and guided by cones, walks 10m forward, turns 90 degrees, walks a further 10m, turns 180 degrees, then follows the same path back to the chair and sits. Result from a single test following one practice trial is recorded.	Pre-intervention, within 5 days post intervention
Activities-specific Balance Confidence Scale summary score	16-item self report measure recording confidence in performing activities during daily life that require balance, on numerical ratings scale, recorded as a percentage (out of 100).	Pre-intervention, within 5 days post intervention
Average daily activity	Mean number of steps per day over 7 days, collected using ankle worn activity monitor.	Pre-intervention, within 5 days post intervention
Four Square Step Test time	Time to complete forwards, lateral and backwards stepping pattern, in s.	Pre-intervention, within 5 days post intervention
Two-minute walk test distance	Walking distance traveled in two minutes, in m.	Pre-intervention, within 5 days post intervention
Protocol acceptability	Likert scale questions and short answer questions to determine acceptability of protocol to participants, assessed qualitatively.	End of intervention week 4
Recruitment feasibility - recruitment rate	Number of participants recruited within one year	From start of recruitment period, to 12 month time point.
Recruitment feasibility - participating clinics	Number of clinics from which at least one participant is recruited.	Through study completion, from start of recruitment period, to end of recruitment period or 30 month time point, whichever is sooner.
Recruitment feasibility - sample characteristics	Sample characteristics of all participants enrolled in the study, regardless of completion.	Through study completion, from start of recruitment period, to end of recruitment period or 30 month time point, whichever is sooner.
Activity data evaluation	Completeness and quality of activity monitor data, measured as number of days with valid (non-erroneous) monitoring data.	Throughout activity monitoring period, over 2 weeks
Maximum relative variability of lateral trunk velocity during uneven terrain in comparison to overground walking	Medial-lateral trunk variability will be quantified during each bout of walking during each session. The maximum relative variability will be calculated as the difference in variability (standard deviation) of peak per-step lateral trunk velocity during UT walking sessions relative to that of overground walking, in m/s.	Through study completion, over 4 weeks
Contour depth at maximum relative variability	Terrain contour depth at which the maximum relative variability was recorded, in m.	Through study completion, over 4 weeks
Maximum relative step width variability during uneven terrain in comparison to overground walking	Step width variability will be quantified during each bout of walking during each session. The maximum relative variability will be calculated as the difference in variability (standard deviation) of step width during UT walking sessions relative to that of overground walking, in m.	Through study completion, over 4 weeks
Single leg stand time	Time standing on one leg up to a maximum of 20s, in s.	Pre-intervention, within 5 days post intervention
Prosthesis Users Survey of Mobility t-score	12-item self report tool measuring prosthesis users' mobility.	Pre-intervention, within 5 days post intervention

Collaborators and Investigators

• Sponsor: University of Nevada, Las Vegas
• Collaborators: United States Department of Defense; National Institutes of Health (NIH); University of Washington; Chapman University
• Investigators: Principal Investigator: Jenny A Kent, PhD, CSci, University of Nevada, Las Vegas

Study record dates

Study Major Dates

• Study Start (Actual): June 26, 2025
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: May 2, 2024
• First Submitted That Met QC Criteria: May 14, 2024
• First Posted (Actual): May 17, 2024

Study Record Updates

• Last Update Posted (Actual): June 23, 2026
• Last Update Submitted That Met QC Criteria: June 18, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries
• Other Study ID Numbers: UNLV-2023-595; CDMRP-OP230011 (Other Grant/Funding Number: Department of Defence)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No