Socket-leg Interface Movements as a Measure of Dynamic Prosthetic Fit for Transtibial Amputees: An Exploratory Study
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Socket-Liner Motion [mm]
研究概览
简要总结
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.
详细描述
Transtibial prosthetic fit strongly influences user comfort, gait quality, and long term functional outcomes. Current clinical assessment methods rely primarily on subjective clinical observation and user feedback. Dynamic socket-leg interface motion (SLM) offers an objective biomechanical indicator of prosthetic fit, but existing studies are limited in sample size, measurement directions, and evaluation across different suspension systems.
This study evaluates SLMs using 3D motion capture, force sensors, and a dynamometer while participants perform three standardized task categories:
isometric rotation tasks to determine rotation resistance and torque thresholds for interface rotation; turning/rotational/pivoting walking tasks to assess functional performance and transverse plane dynamics; and treadmill walking at multiple speeds to quantify proximal-distal pistoning and gait kinematics.
Each participant is tested using three suspension system conditions (pin-lock, passive vacuum, active vacuum), starting with their preferred suspension system followed by a counterbalanced order to minimize bias. A transparent "test socket" replicating the participant's own socket allows interface visualization and marker tracking without altering the intended use of the prosthesis. The investigational device consists only of CE marked components used within their intended purpose.
Participants attend one study visit with a duration of approximately 4 to 5 hours, including prosthesis adjustment and placement, marker setup, data collection across all three task categories and with all three suspension system conditions.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 16 Years 至 —（Child, Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •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)
排除标准
- •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
- •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
研究组 & 干预措施
Single Cohort: Three Suspension Systems
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.
干预措施: Pin-Lock Suspension System (Device)
Single Cohort: Three Suspension Systems
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.
干预措施: Passive Vacuum Suspension System (Device)
Single Cohort: Three Suspension Systems
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.
干预措施: Active Vacuum Suspension System (Device)
结局指标
主要结局
Socket-Liner Motion [mm]
时间窗: Within 1 hour after fitting the suspension system
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.
Proximal-distal Socket-Leg Motion [mm]
时间窗: Within 1 hour after fitting the suspension system
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.
次要结局
- 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)
- Perceived Functional Ability(Within 1 hour after fitting the suspension system)
- Prosthesis Satisfaction Score(Within 1 hour after fitting the suspension system)