Tremor

An involuntary, rhythmic shaking movement of one or more parts of the body, most commonly affecting the hands. Tremor can result from various conditions including essential tremor, Parkinson's disease, multiple sclerosis, stroke, or medication side effects, and its severity can range from barely noticeable to significantly impairing fine motor control. In accessibility contexts, tremor poses particular challenges for computer input: it can cause unintended mouse movements, difficulty clicking small targets, accidental double-clicks, and problems with touchscreen interaction where the finger may land imprecisely or trigger unintended gestures. Assistive technology solutions for tremor include mouse smoothing filters that dampen erratic movements, enlarged targets, dwell-click software that registers a click when the cursor remains stationary, and adaptive keyboards with adjustable key repeat rates and acceptance delays.