Hand-eye coordination
I recall reading an article recently about how a change from 1G gravity really messes up our physical coordination, as in being able to catch a bouncing or flying ball. The human brain just naturally assumes a 1G force acting on the object's trajectory and the hand reaches out accordingly...and misses.
This will be a funny sight (too bad we won't live long enough to see it):
The first baseball games played by Martian colonists will be a comedy of errors, as players misjudge pop flies and what would be easy infield grounders on Earth. Lots of strikeouts too, as the batters consistently swing under the pitch...
