A patient's arm resists hard the moment you move it fast, then suddenly gives — that jump from resistance to release is what clinicians are trained to catch during a standard neuro screening. Clasp knife spasticity shows up specifically at speed, which is exactly why slow, careful movement during an exam can miss it entirely. Manthanhub covers the mechanics behind this pattern in plain terms, connecting the reflex science to what it actually feels like under your hands. Students and new clinicians often mix this up with plain old stiffness at first. Once the velocity-dependent piece clicks, the two stop looking anything alike.
Speed-dependent resistance pattern
Easy to miss with slow exams
Distinct from ordinary stiffness
