Article in the New York Times that may require registration.
All the fingers (and thumb) tend to work as a unit.
Not only are the ring and pinky fingers physically tethered together by a shared tendon, as anatomists long have known; measurements of neuromuscular activation patterns have shown that all fingers, including the ones with the greatest structural autonomy, the thumb and index finger, are keenly responsive to every flex and twitch of their neighboring digits.
“Even when you think you’re moving just one finger,” said Marc H. Schieber, a professor of neurology and neurobiology at the University of Rochester Medical Center, “you’re really controlling your entire hand.”
The pianist playing Ravel or the typist clacking on Blogspot? “People tend to think, they’re hitting one key at a time, so they must be moving one finger at a time to hit that key,” Dr. Schieber said. “But really, all the fingers are in motion all the time.”
For every keystroke, there’s a movement of every finger. “Some of the movement is to strike the key,” Dr. Schieber said, “others to lift fingers back up and away from the key, others to hold them away.”
The brain also treats the hands as unified tools, often in ways of which we’re not consciously aware. Scientists have shown that our hands start assuming the necessary configuration as soon as the brain initiates an activity — if not a micromoment earlier. If we’re reaching for a water bottle, the hand takes on a generic open cupping shape, refining the curvature and angle of the gesture as the hand closes in on the bottle.
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Give the thumb two thumbs up. “When we lose a thumb, we lose half if not more of the functionality of the hand,” said Lynette Jones, a hand specialist at the Massachusetts Institute of Technology. This is why people who have lost a thumb often opt to have another finger or a great toe transplanted into its place.
The hard-working digit pays a price for its diligence. In this country, said Dr. Steven J. McCabe, the past president of the American Association for Hand Surgery, almost everyone ends up with arthritis at the base of the thumb by late middle age.