1. An ultrasonic diagnostic imaging system for diagnosing myocardial motion comprising: a probe configured to transmit ultrasonic waves into a heart and receives echoes in response; an image processor responsive to the echoes and configured to produce a sequence of images of a myocardium over at least a portion of a heart cycle; a speckle tracker, responsive to the sequence of images, which is configured to determine motion of a plurality of segments of the myocardium; a recruitment processor, responsive to the motion of the segments, which is configured to produce an indicator of cumulative participation of the plurality of segments toward a percentage of a full displacement of the myocardium during the heart cycle and of relative times of participation of the segments in myocardial motion relative to the percentage of full displacement during the heart cycle; and a display coupled to the recruitment processor and configured to display the indicator.