One of the common artefacts that make electrocardiographic interpretation difficult is due to tremor of the somatic muscles. This produces an irregular vibration of the baseline that may partially or completely obscure the smaller waves of the tracing. Clinical electrocardiography is feasible only because no large muscle masses, except the heart muscle, are in motion in the normal subject at rest. Tremor is a troublesome factor in many nervous patients but is intensified in thyrotoxicosis and is particularly intense in patients with a neurological disturbance such as paralysis agitans (parkinsonism). It has previously been recognized that the influence of tremor can be minimized in routine tracings by the application of the standard limb electrodes to the forearm and inner aspect of the lower leg rather than to the wrist and the ankle. This reduces but does not eliminate the effect of tremor in most cases.
A simple technique for the