Change in handlebar design compared with old bikes

Modern bikes usually have more-or-less straight handlebars with the grips
roughly at right-angles to the direction of travel. Looking at older bikes
in museums and in old photos, it seems that at one time the fashion was for
handlebars to be C-shaped, with the grips roughly in the direction of travel
and at right angles to the main handlebar.

What was the reason for the change? Has the anatomy of people changed? Did
they once find it easier to rotate their wrists through 90 degrees with
their thumbs uppermost / forwards to fit C-shaped handlebars than to put
them in (for me) the natural position with the knuckles uppermost and thumbs
facing each other and therefore gripping handlebars that are at right-angles
to the direction of travel?

I'm talking about "straight" handlebars for touring / general purpose bikes
rather than drop handlebars for racing bikes - the latter have always had
the grip suited to hands in the thumbs-uppermost position.

On Tue, 9 Sep 2014 17:14:31 +0100
"NY" wrote:

Modern bikes usually have more-or-less straight handlebars with the
grips roughly at right-angles to the direction of travel. Looking at
older bikes in museums and in old photos, it seems that at one time
the fashion was for handlebars to be C-shaped, with the grips roughly
in the direction of travel and at right angles to the main handlebar.

What was the reason for the change? Has the anatomy of people
changed?

When bikes had rod operated brakes the handlebar shape was dictated by
the need to have the brake lever approximately perpendicular to its
hinge. When rods were mostly replaced by cables in the second half of
C20 this was no longer necessary. Plenty of modern bikes still have a
similar grip position - as well as racers with drop bars there are
mountain bikes with bar end extensions, and tourers and roadsters with
moustache/butterfly bars.