The present invention includes an apparatus having an elongated probe with proximal and distal ends and a sensor coupled to the elongated probe and configured to generate signals used for determining location and orientation coordinates of the elongated probe. The apparatus further includes a processor operatively connected to the sensor, and being configured to measure a cumulative angle of rotation that is applied by an operator to the proximal end of the probe while the operator manipulates the proximal end so as to move the distal end within a body of a patient. The apparatus also includes an output device operatively connected to the processor, and configured to present an indication of the cumulative angle of rotation to the operator.
