Prostheses are used to at least partly restore the body after limb amputation. Making the user accepting the prosthetic device as part of his or her body, i.e., inducing prosthesis embodiment, has been identified as major aim of prosthetic treatment. However, up to now, there is no consensus about the psychometric nature of prosthesis embodiment in limb amputees. In the present study, 118 unilateral lower limb amputees using a prosthesis were asked to complete an online questionnaire targeting prosthesis embodiment. Principal axis factoring revealed the factor structure of prosthesis embodiment, i.e., Ownership/Integrity, Agency, and Anatomical Plausibility, which resembles the embodiment structure previously found in normally-limbed participants. The majority of amputees achieved substantial embodiment of the prosthesis as assessed with the final version of the newly developed Prosthesis Embodiment Scale. Internal consistency was excellent, and test-retest reliability was acceptable, while the instrument was also sensitive for new prosthetic supply. Validation on the basis of relationships to locomotor capability, prosthesis satisfaction, and prosthesis adjustment was performed. The Prosthesis Embodiment Scale could be a valuable tool for the phenomenological assessment of successful body-prosthesis interaction in rehabilitative and research contexts, the latter which might further benefit from the comparability of psychometrically evaluated data.
Control of a Powered Lower Limb Prosthetic Device