Dystonia models predict that the range of motion in voluntary arm-swing movement should be reduced in dystonia; with certain level of compensation by increasing the voluntary command, the range of movement can be recovered. In the non-impaired condition, the joint was voluntarily swinging at 1Hz with approximately 50° range of movement; the muscles are activated using alternating descending commands at 1Hz as depicted in Fig. 1 and thus generate alternating EMG bursts. In the TONIC model, we maintained the level and frequency of the 1Hz voluntary command, but added a tonic input with 80% of the peak-to-peak magnitude of the voluntary command. This reduces the movement range by 21%, which can be recovered by compensating the voluntary command by 67% of its original magnitude. In the HI-GAIN model, a 4.7 times increase in the synaptic gain of cortical neuron pool decreased the movement range by 56%, which can be recovered by compensating the voluntary command by 100%.