Functional assessment of current upper limb prostheses: An integrated clinical and technological perspective

Abstract

Although recent technological developments in the field of bionic upper limb prostheses, their rejection rate remains excessively high. The reasons are diverse (e.g. lack of functionality, control complexity, and comfortability) and most of these are reported only through self-rated questionnaires. Indeed, there is no quantitative evaluation of the extent to which a novel prosthetic solution can effectively address users’ needs compared to other technologies. This manuscript discusses the challenges and limitations of current upper limb prosthetic devices and evaluates their functionality through a standard functional assessment, the Assessment of Capacity for Myoelectric Control (ACMC). To include a good representation of technologies, the authors collect information from participants in the Cybathlon Powered Arm Prostheses Race 2016 and 2020. The article analyzes 7 hour and 41 min of video footage to evaluate the performance of different prosthetic devices in various tasks inspired by activities of daily living (ADL). The results show that commercially-available rigid hands perform well in dexterous grasping, while body-powered solutions are more reliable and convenient for competitive environments. The article also highlights the importance of wrist design and control modality for successful execution of ADL. Moreover, we discuss the limitations of the evaluation methodology and suggest improvements for future assessments. With regard to future development, this work highlights the need for research in intuitive control of multiple degrees of freedom, adaptive solutions, and the integration of sensory feedback.

A multifaceted suite of metrics for comparative myoelectric prosthesis controller research

“…Without question, our earlier work identified important omissions in the collective of metrics commonly used for prosthesis control appraisal, even amongst those of established task-based assessments meant to mimic activities of daily living. Such functional assessments include the Box and Blocks Test [ 33 ], Jebsen-Taylor Hand Function Test [ 34 ], Activities Measure for Upper Limb Amputees [ 35 ], Southampton Hand Assessment Procedure [ 36 ], and Assessment of Capacity for Myoelectric Control [ 37 , 38 ]. These assessments typically require users to interact with a variety of objects (e.g., grasp, move, rotate, release of objects), but the scores used to summarize arm function are limited—either based on task completion durations [ 34 , 36 ], number of objects moved [ 33 ], or a trained rater’s assessment [ 35 , 37 , 38 ].…”

“…Such functional assessments include the Box and Blocks Test [ 33 ], Jebsen-Taylor Hand Function Test [ 34 ], Activities Measure for Upper Limb Amputees [ 35 ], Southampton Hand Assessment Procedure [ 36 ], and Assessment of Capacity for Myoelectric Control [ 37 , 38 ]. These assessments typically require users to interact with a variety of objects (e.g., grasp, move, rotate, release of objects), but the scores used to summarize arm function are limited—either based on task completion durations [ 34 , 36 ], number of objects moved [ 33 ], or a trained rater’s assessment [ 35 , 37 , 38 ]. Such scores cannot yield a complete understanding of the quality of participants’ hand, wrist, and arm movements [ 29 ].…”

“…Here, either non-disabled participants wearing a simulated prosthesis or actual myoelectric prosthesis users, are required to perform upper limb tasks that mimic activities of daily living. One common clinical control assessment technique, known as the Assessment of Capacity for Myoelectric Control, has a trained rater assess control during functional task execution [ 37 , 38 ]. However, a trained rater may not always be available.…”

Does Exerting Grasps Involve a Finite Set of Muscle Patterns? A Study of Intra- and Intersubject Variability of Forearm sEMG Signals in Seven Grasp Types

“…The more accurate the information about a person's intention to perform a particular grasp or movement, the better the accuracy of the telerobotics or teleoperation, or the greater the usability of the prosthesis or assistive device [19]. A concerning issue is the intuitiveness of the control of such devices [20], which can be achieved if users do not have to change the way they do the tasks under normal conditions. However, there are several handicaps that hinder this intuitive control [21]: complexity of executing the hand grasp; redundancy of the neuromotor system; the existence of intra-and intersubject variability when doing the same task goal; the many sEMG characteristics that can be used to control different devices [22].…”

The LIBRA NeuroLimb: Hybrid Real-Time Control and Mechatronic Design for Affordable Prosthetics in Developing Regions

“…Even if covered, insurance typically applies to generic hook-type prostheses for specific amputation levels. With each amputation being unique, factors like evolution time, muscle condition, hypersensitivity, and ankylosis must be considered [ 28 ]. Customized models entail pre-prosthetic and post-prosthetic phases, leading to increased development costs.…”