NCT07521891

Brief Summary

This exploratory interventional study investigates dynamic prosthetic fit in unilateral transtibial prosthesis users by objectively measuring socket-leg interface movements (SLMs) during functional activities. During one single study visit, participants complete standardized laboratory tasks using three different suspension systems (pin-lock, passive vacuum, and active vacuum) applied to a transparent replica of their current prosthetic socket. Motion capture, force measurements, and patient-reported outcomes are used to evaluate how suspension systems influence interface motion, rotation resistance, gait characteristics, and user comfort. The study aims to improve clinical understanding of prosthetic fit and support more informed prosthetic decision-making in routine care.

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
20

participants targeted

Target at below P25 for not_applicable

Timeline
44mo left

Started Apr 2026

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress1%
Apr 2026Dec 2029

First Submitted

Initial submission to the registry

March 5, 2026

Completed
1 month until next milestone

First Posted

Study publicly available on registry

April 13, 2026

Completed
7 days until next milestone

Study Start

First participant enrolled

April 20, 2026

Completed
10 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 27, 2027

Expected
2.8 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 27, 2029

Last Updated

April 13, 2026

Status Verified

April 1, 2026

Enrollment Period

10 months

First QC Date

March 5, 2026

Last Update Submit

April 7, 2026

Conditions

Transtibial Amputation - Unilateral

Keywords

Transtibial amputationLower-limb prosthesisProsthetic socket fit3D motion captureProsthesis comfortProsthetic rotation resistancePistoningProsthetic suspension systemsProsthetic alignmentgait

Outcome Measures

Primary Outcomes (2)

  • Socket-Liner Motion [mm]

    Socket-liner motion is quantified using a 3D optical motion-capture system to measure the relative movement between the prosthetic socket and liner during functional activities. Motion is recorded in millimeters (mm). Typical motion values are expected to fall within the range of 0-20 mm.

    Within 1 hour after fitting the suspension system

  • Proximal-distal Socket-Leg Motion [mm]

    Proximal-distal Socket-Leg Motion is quantified using a 3D motion-capture system to measure the relative movement between the prosthetic socket and the remaining leg during functional activities. Motion is recorded in millimeters (mm). Typical motion values are expected to fall within the range of 0-30 mm.

    Within 1 hour after fitting the suspension system

Secondary Outcomes (7)

  • Torque Required to Initiate Socket-Liner Rotation [Nm]

    Within 1 hour after fitting the suspension system

  • Step length [cm]

    Within 1 hour after fitting the suspension system

  • Step length asymmetry index

    Within 1 hour after fitting the suspension system

  • Gait velocity [m/s]

    Within 1 hour after fitting the suspension system

  • Patient-Reported Socket Comfort Score (SCS)

    Within 1 hour after fitting the suspension system

  • +2 more secondary outcomes

Other Outcomes (5)

  • Socket-Leg rotation [degrees]

    Within 1 hour after fitting the suspension system

  • Step length [% of bodyheight]

    Within 1 hour after fitting the suspension system

  • Knee angle [degrees]

    Within 1 hour after fitting the suspension system

  • +2 more other outcomes

Study Arms (1)

Single Cohort: Three Suspension Systems

EXPERIMENTAL

Participants with unilateral transtibial amputation will attend one study visit at the research site. During this visit, they will complete three movement tasks-treadmill walking, overground turning, and isometric leg rotation-while using three different prosthetic suspension systems in a partly randomized order (pin lock, passive vacuum, and active vacuum). Each of the three movement tasks will be performed with each of the three suspension systems. Biomechanical, performance, and patient-reported outcomes will be recorded for each suspension condition.

Device: Pin-Lock Suspension SystemDevice: Passive Vacuum Suspension SystemDevice: Active Vacuum Suspension System

Interventions

Pin-Lock Suspension SystemDEVICE

Participants perform all tasks using a pin-lock suspension system applied to their test socket.

Single Cohort: Three Suspension Systems
Active Vacuum Suspension SystemDEVICE

Participants perform all tasks using an active vacuum suspension system applied to their test socket.

Single Cohort: Three Suspension Systems
Passive Vacuum Suspension SystemDEVICE

Participants perform all tasks using a passive vacuum suspension system applied to their test socket.

Single Cohort: Three Suspension Systems

Eligibility Criteria

Age16 Years+
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

  • Age ≥16 years
  • Unilateral transtibial amputation
  • Activity level K2-K4
  • Actively using a prosthesis for ≥12 months
  • Ability to understand and communicate in Norwegian (oral and written)
  • Digital file of current socket model available (required for test socket fabrication)

You may not qualify if:

  • Use of a thigh corset attached to the prosthesis
  • Requirement of a walker for ambulation
  • Open wounds, skin ulcers, or blisters on the residual limb
  • No liner
  • Missing digital socket model file
  • Medical advice to avoid physical activity similar to study tasks
  • Other medical conditions that may worsen with activity and have not been cleared by a healthcare professional

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

NTNU's Movement analysis laboratory at Helgasetr

Trondheim, 7030, Norway

Location

Study Officials

  • Karin Roeleveld

    National Taiwan Normal University

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Karin Roeleveld, PhD

CONTACT

+47 48177279karin.roeleveld@ntnu.no

Maria J Lequerica, MSc

CONTACT

+47 48684299maria.j.lequerica@ntnu.no

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
OTHER
Intervention Model
SINGLE GROUP
Model Details: All participants complete the same set of laboratory tasks under three suspension system conditions (pin-lock, passive vacuum, active vacuum). The sequence of conditions is partly determined by the participant's current or preferred suspension system, which is always tested first, and partly counterbalanced for the remaining two suspension systems to reduce order effects. Each participant serves as their own control.
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 5, 2026

First Posted

April 13, 2026

Study Start

April 20, 2026

Primary Completion (Estimated)

February 27, 2027

Study Completion (Estimated)

December 27, 2029

Last Updated

April 13, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will not share

Individual participant data (IPD) from this study cannot be shared because the data are not anonymous. According to REK regulations and GDPR requirements, the research team must retain the identification key for as long as the data are used for research purposes. As long as this key exists, the dataset is considered identifiable, and sharing identifiable or potentially re-identifiable data externally is not permitted. Therefore, IPD cannot be shared.

Locations

NO(1)