Comparing the Attentional Demands and Functional Outcomes in People With Transradial Amputation

Purpose

Different ways of controlling an upper-limb prosthesis can affect how easy it is to use and how helpful it is in everyday activities. One common method, called direct control, uses signals from two muscles and can make switching between movements difficult. Another clinically available option, called pattern recognition control, uses signals from several muscles to better understand the user's intended movement and may feel more natural to use. This study compares these two control methods to see how they affect function for adults with below-the-elbow limb loss.

Conditions

  • Amputation
  • Prosthesis Use

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 18 years of age or older - Unilateral transradial limb loss - At least 6 months since loss - Previous or current use of a myoelectric device for 3 months or longer - Use of a prosthesis at least 4 days each week - Ability to read, write, and understand English - Willingness to use each control strategy as primary device for 3 months each (6 months commitment total)

Exclusion Criteria

  • Any health condition that would prevent safely completing trial activities - Discontinued use of a myoelectric prosthesis due to non-financial reasons

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Intervention Model Description
This study uses a 6-month crossover trial to compare two clinically established myoelectric control strategies for upper-limb prostheses: pattern recognition control (PRC) and conventional direct control (DC). Adult participants with unilateral transradial limb loss who are current prosthesis users will serve as their own controls by using both control methods during the study period. The intervention condition is PRC, which utilizes EMG signals from multiple electrodes distributed across the residual limb and applies pattern-classification algorithms to determine intended movements. The control condition is DC, a two-site strategy that relies on relative EMG signal amplitude from an antagonistic muscle pair. All participants will be provided with a transradial prosthesis equipped with a wrist unit and multi-function hand. Functional performance under PRC and DC will be directly compared to evaluate relative advantages and limitations of each control approach.
Primary Purpose
Supportive Care
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Active Comparator
Pattern recognition controller (PRC) arm method intervention first and then the DC intervention 		Participants randomized to this condition will first try the PRC controller for 3 months. Afterwards, participants will try the DC controller for 3 months. Participants in the study will be provided with a transradial prosthesis with either a choice of a wrist + electronic terminal device (ETD) OR a multi-articulating hand terminal device. The prosthesis will be fabricated to switch between the two control conditions.
  • Device: Training with PRC
    All participants will receive in-person training with an onsite study prosthetist for the assigned controller strategy. The purpose of the training will be to instruct users on the care of the device formally and to achieve a basic level of functional performance. Training will be individualized according to clinical discretion consistent with clinical practice. Training will consist of up to four sessions to facilitate participants' use of the assigned controller system. The number of sessions will be competency-based (i.e., determined by the ability of each participant to explain or perform specified tasks). A standardized protocol and training checklist have been developed by clinical subject matter experts (i.e., upper limb prosthetists and occupational therapists).
  • Device: Training with DC
    All participants will receive in-person training with an onsite study prosthetist for the assigned controller strategy. The purpose of the training will be to instruct users on the care of the device formally and to achieve a basic level of functional performance. Training will be individualized according to clinical discretion consistent with clinical practice. Training will consist of up to four sessions to facilitate participants' use of the assigned controller system. The number of sessions will be competency-based (i.e., determined by the ability of each participant to explain or perform specified tasks). A standardized protocol and training checklist have been developed by clinical subject matter experts (i.e., upper limb prosthetists and occupational therapists).
  • Device: PRC Device use in community and home
    After the training sessions, all subjects will use the PRC device in their homes, just in a different order.
  • Device: DC Device use in community and home
    After the training sessions, all subjects will use the DC device in their homes, just in a different order.
Active Comparator
DC intervention first and then the Pattern recognition controller (PRC) arm method intervention 		Participants randomized to this condition will first try the DC controller for 3 months. Afterwards, participants will try the PRC controller for 3 months. Participants in the study will be provided with a transradial prosthesis with either a choice of a wrist + electronic terminal device (ETD) OR a multi-articulating hand terminal device. The prosthesis will be fabricated to switch between the two control conditions.
  • Device: Training with PRC
    All participants will receive in-person training with an onsite study prosthetist for the assigned controller strategy. The purpose of the training will be to instruct users on the care of the device formally and to achieve a basic level of functional performance. Training will be individualized according to clinical discretion consistent with clinical practice. Training will consist of up to four sessions to facilitate participants' use of the assigned controller system. The number of sessions will be competency-based (i.e., determined by the ability of each participant to explain or perform specified tasks). A standardized protocol and training checklist have been developed by clinical subject matter experts (i.e., upper limb prosthetists and occupational therapists).
  • Device: Training with DC
    All participants will receive in-person training with an onsite study prosthetist for the assigned controller strategy. The purpose of the training will be to instruct users on the care of the device formally and to achieve a basic level of functional performance. Training will be individualized according to clinical discretion consistent with clinical practice. Training will consist of up to four sessions to facilitate participants' use of the assigned controller system. The number of sessions will be competency-based (i.e., determined by the ability of each participant to explain or perform specified tasks). A standardized protocol and training checklist have been developed by clinical subject matter experts (i.e., upper limb prosthetists and occupational therapists).
  • Device: PRC Device use in community and home
    After the training sessions, all subjects will use the PRC device in their homes, just in a different order.
  • Device: DC Device use in community and home
    After the training sessions, all subjects will use the DC device in their homes, just in a different order.

Recruiting Locations

Hanger Inc.
Austin, Texas 78758
Contact:
Shane R. Wurdeman, PhD
281-829-4746
swurdeman@hanger.com

Virginia Commonwealth University
Richmond, Virginia 232398
Contact:
Tiffany Amos
804-828-4766
tdclory@vcu.edu

More Details

Status
Recruiting
Sponsor
Virginia Commonwealth University

Study Contact

Shane R. Wurdeman, PhD
281-829-4746
swurdeman@hanger.com

Detailed Description

Pattern recognition controller (PRC) systems for upper-limb prostheses are a clinically established alternative to conventional direct control (DC) systems. For decades, two-site DC has been the primary method for controlling myoelectric upper-limb prosthetic devices. DC relies on surface electromyography (EMG) recordings from two control sites, typically an antagonistic muscle pair in the residual limb, and uses relative signal amplitude to generate movement commands for the prosthesis. PRC is a more recent, clinically established control strategy developed to address several limitations associated with DC. Rather than depending on isolated activation of two muscle sites, PRC captures EMG signals from multiple sensors across the residual limb and uses pattern-classification algorithms to identify the user's intended movement. By incorporating information from multiple EMG channels, PRC may provide more intuitive and natural control, support a broader range of wrist and terminal device motions, and reduce reliance on non-intuitive switching strategies-particularly during tasks requiring rapid transitions between movements. PRC systems also enable on-demand recalibration, allowing users to adjust control performance in response to day-to-day changes in socket fit or electrode positioning. Although both PRC and DC systems are clinically established and have been used in practice, this study provides an opportunity to directly compare two clinically established control strategies. This trial will evaluate the functional advantages and disadvantages of PRC relative to DC when used by adults with unilateral transradial limb loss.