Rigidity

Increased muscle tone causing stiffness and resistance to passive movement, commonly experienced in Parkinson's Disease and other neurological conditions. Unlike spasticity (which varies with movement speed), rigidity is constant throughout the range of motion. Rigidity affects the limbs, neck, and trunk, making movements feel effortful and contributing to reduced dexterity. For digital accessibility, rigidity can impair fine motor control needed for precise pointing, small key presses, and touchscreen gestures. Users with rigidity may benefit from larger touch targets, reduced need for precise movements, and keyboard alternatives that don't require sustained pressure.