Fig. 1

Rigidity quantification. a Robotic manipulandum. A participant is instructed to hold onto the handle as a motor moves it in a sinusoidal rhythm. Torque is measured through a strain gauge that is attached to the motor. b Estimating rigidity from torque data. Torque data is low pass filtered with a cutoff frequency of 20Hz and measured over a 20 s trial after a 5 s warm-up. c A patient’s RoMaR value is calculated by measuring the slope of the impulse of the filtered torque signal (red line)