Figure 3.

Tremorogram of a patient with jerky tremulous movements of the right thigh. The surface EMG recordings are from the quadriceps and adductor muscles of the thigh and tibialis anterior and gastrocnemius muscles of the leg. In the upper trace, the recording is at rest when the patient was asked to relax without any voluntary movements of the leg. In the lower trace, the patient was asked to move the toes up and down. It can be seen that there was an irregular tremor of approximately 7.5 Hz with variable duration of the EMG bursts as well as inter-burst intervals. When the patient was asked to voluntarily move the toes, this tremor of the thigh totally disappeared, suggesting distractibility and modulation, thereby supporting a non-organic basis of these movements.