In order to evaluate spinal spasticity quantitively, we recorded the T waves of the patella tendon reflex following the Jendrassik manoeuvre and at rest, and measured the ratio of the amplitude of T wave (J/R ratio).
The J/R ratio of 8 normal subjects ranged from 1.89 to 10.3 (mean: 4.60), and in 12 patients with spinal spasticity ranged from 1.0 to 1.88 (mean: 1.28).
The more the spasticity increased, the closer to 1.0 the J/R ratio tended to be.
