Another article saying that writing by hand matters, this time focusing on younger students:

http://www.nytimes.com/2014/06/03/science/whats-lost-as-handwriting-fades.html
What’s Lost as Handwriting Fades
By MARIA KONNIKOVA
New York Times
JUNE 2, 2014

Quote
New evidence suggests that the links between handwriting and broader educational development run deep.

Children not only learn to read more quickly when they first learn to write by hand, but they also remain better able to generate ideas and retain information. In other words, it’s not just what we write that matters — but how.

“When we write, a unique neural circuit is automatically activated,” said Stanislas Dehaene, a psychologist at the Collège de France in Paris. “There is a core recognition of the gesture in the written word, a sort of recognition by mental simulation in your brain.