People with Severe Motor Disabilities

A term used in assistive technology and human-robot interaction research to describe individuals whose motor impairments are severe enough that they cannot reliably use their hands or arms for everyday tasks, and who therefore depend on hands-free control modalities such as eye tracking, brain-computer interfaces, sip-and-puff switches, or voice input. Conditions leading to PSMD status include locked-in syndrome, late-stage amyotrophic lateral sclerosis (ALS), advanced multiple sclerosis, high-level spinal cord injury, and severe cerebral palsy. The PSMD framing is used in accessibility research to identify a stakeholder group whose needs differ qualitatively from users with lighter motor impairments and who are often under-represented in studies of assistive devices despite being the primary intended audience.