Pub. date: 2010 | Online Pub. Date: December 16, 2009 | DOI: 10.4135/9781412972000 | Print ISBN: 9781412940818 | Online ISBN: 9781412972000| Publisher:SAGE Publications, Inc.About this encyclopedia
James R. Lackner
When a pitcher throws a fastball to a batter, the velocity of the ball can be as high as 100 miles per hour (mph). A few milliseconds difference in the timing of ball release can make the difference between a strike and a ball. The control of the ongoing configuration of the arm and of the fingers releasing the ball thus has to be precise. Such precision is actually characteristic of most of our hand movements. For example, when we run our hands over a stationary surface, we will perceive the surface to be stationary; by contrast, if it is moving, we will perceive it to be moving and sense the direction of its motion. The ability to make such distinctions means that we are able to discriminate the stimulation of the skin of our hand that is caused by our own arm motion from that resulting from motion of ...