Date Published: January 31, 2019
Publisher: Public Library of Science
Author(s): Emily L. Graczyk, Anisha Gill, Dustin J. Tyler, Linda J. Resnik, Mariella Pazzaglia.
The experience of upper limb loss involves loss of both functional capabilities and the sensory connection of a hand. Research studies to restore sensation to persons with upper limb loss with neural interfaces typically measure outcomes through standardized functional tests or quantitative surveys. However, these types of metrics cannot fully capture the personal experience of living with limb loss or the impact of sensory restoration on this experience. Qualitative studies can demonstrate the viewpoints and priorities of specific persons or groups and reveal the underlying conceptual structure of various aspects of their experiences.
Following a home use trial of a neural-connected, sensory-enabled prosthesis, two persons with upper limb loss were interviewed about their experiences using the sensory restoration system in unsupervised, unconstrained settings. We used grounded theory methodology to examine their experiences, perspectives, and opinions about the sensory restoration system. We then developed a model to describe the impact of sensation on the experience of a hand for persons with upper limb loss.
The experience of sensation was complex and included concepts such as the naturalness of the experience, sensation modality, and the usefulness of the sensory information. Sensation was critical for outcome acceptance, and contributed to prosthesis embodiment, confidence, reduced focus and attention for using the prosthesis, and social interactions. Embodiment, confidence, and social interactions were also key determinants of outcome acceptance. This model provides a unified framework to study and understand the impact of sensation on the experience of limb loss and to understand outcome acceptance following upper limb loss more broadly.
Following an upper limb amputation, many persons utilize a prosthesis to aid them in daily life. However, approximately 21% of adults with upper limb loss do not use prostheses at all, in part because they feel that current prosthetic devices do not meet their needs . This may be partially due to the fact that commercially available prostheses provide mobility and function, but do not restore the sensory capabilities of the hand. Approximately 85% of prosthesis rejecters identify the lack of sensory feedback as a factor in their decision not to wear a prosthesis [2,3]. Without sensory feedback to regulate grip force and determine material properties of objects, myoelectric prosthesis users must rely to a larger extent on visual and auditory feedback from observing the prosthesis, resulting in functional deficits [4–10]. In addition, sensory feedback aids in prosthesis incorporation into the body, and may contribute to the psychosocial experience of having a hand [11,12].
Each category included in the theoretical model is described below, with examples from the coded text to illustrate the main concepts contained in each category.