Towards Human-Centered Rehabilitation: A Focus on Embodiment and User Perception of Upper Limb Prostheses - PROJECT SUMMARY Loss of an upper limb can greatly impact the ability to perform daily tasks, work, and participate in social contexts, so a major goal of rehabilitation for individuals with upper limb loss is to facilitate their full engagement in all aspects of life. While a common research objective is to support these individuals through the development of more advanced prosthetic limbs, the experience of disability is also shaped by physical, biological, and social factors beyond the prosthesis itself. A human-centered approach to rehabilitation that addresses these interconnected factors could be more effective for enabling functional success in this population. An emerging concept that may be useful in this application is embodiment, or the perception that the prosthesis is part of the user’s body, but the relative importance of embodiment compared to other factors that influence prosthesis use is not well-understood. In particular, it is unknown if prosthesis embodiment is actually a desired outcome among individuals with upper limb loss. It is also unclear whether all individuals are equally capable of embodying their prosthesis, or whether they differ in their ability to acquire the requisite skills that would facilitate embodiment. There are numerous sources of error during prosthesis use, which come from both the user and the prosthesis, that could inhibit the experience of embodiment if individuals are unable to adequately compensate. Thus, variance in the experience of embodiment between individuals may be related to how they detect and adapt to with these error sources. The goal of this proposal is to better understand variation in the desire and ability of individuals with upper limb loss to experience prosthesis embodiment. In Aim 1, we will explore how individuals with upper limb loss perceive the necessity of prosthesis embodiment. We will conduct semi-structured interviews related to their experience or lack of experience with embodiment, using questions developed in consultation with individuals with upper limb loss. In Aim 2, we will examine the role of user-related and prosthesis-related error in determining movement adaptation and embodiment in upper limb prosthesis users. This will be accomplished using virtual cursor control tasks to separate the error sources and quantify embodiment, along with correlations to assess whether individual skill in error compensation is associated with stronger embodiment. Successful completion of this proposal will provide insight on the conditions under which upper limb prosthesis embodiment arises and the extent to which embodiment is necessary for optimal engagement in different life activities. This information can direct future assessments of prosthesis use to focus on the most impactful contributors to functional success. Ultimately, these assessments could support the development of prosthesis design and training protocols tailored to individual needs and preferences.
