ABSTRACTThis article contributes to the discussion of how people with limited communication means become active participants in the assessment of welfare technologies. The article combines ethnomethodology with insights from Science and Technology Studies and emphasises the situated and multimodal practices that constitute the trial as a joint activity in which the impaired person becomes a competent participant and independent walker. The analysis is based on video recordings from a case study in which a person with brain injury is trying out a new type of walking help. The trial is understood as a situated learning process in which the participants prepare, enact and assess the performance of the technology-supported walking. The article distinguishes two iterative phases in which the impaired person is constituted as an independent walker: the adjustment and assessment of a body–device relation and, further, the performance and assessment of the activity the user can perform.