Constraint-Induced Movement Therapy Simulator

Protocol Controls

Mitt constraint on unaffected arm 70%

Forced-use practice 6.0 h/day

Scrub day Day 0

Motor Cortex State

Cortical territory A

20.0%

Motor function F

11.5%

Day of protocol

0 / 21

How it works

After a stroke, the hand's cortical representation in primary motor cortex (M1) shrinks. Because the unaffected hand is easier to use, patients default to it — a spiral called learned non-use that starves the affected map of activity. Constraint-Induced Movement Therapy (CIMT) breaks the spiral by restraining the unaffected arm in a mitt and forcing hours of intensive practice with the affected one, driving competitive, use-dependent cortical reorganization (Nudo et al.).

dA/dt = k·Ua·(1 − A) − d·Uu·A
Ua = C · H/8           (forced-use time fraction)
Uu = (1 − C) · (8 − H)/8  (unaffected-hand time fraction)
F  = 100 · A^0.7        (saturating function-vs-territory map)

A — affected-hand territory in M1, normalized to pre-stroke baseline (1.0 = fully restored).
Mitt constraint C — fraction of the day the unaffected arm is restrained; raising it removes the competing "easy" pathway and reallocates use-time toward the affected limb.
Forced-use hours H — daily structured practice dose; standard CIMT protocols run ≈ 6 h/day for 10–15 consecutive days.
Shaping — breaking tasks into small, just-beyond-reach steps with immediate feedback (vs. plain repetition) raises the learning-rate constant k by 40%, matching the outcome gap reported for shaping vs. non-shaping CIMT trials.
The grid below is a schematic patch of M1 hand cortex: cube height/color = local synaptic weight, radiating outward from a seed point as A grows — a stand-in for the expanding hand map seen on real motor-cortex mapping studies.

Day 0 / 21

Affected-hand territory Unclaimed cortex

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