Lethargic fights ?

[Whacker]

Which makes me wonder why all those armours in museums tend to be very small?

Gruessen Sie Herr Husar

I think we all know what the most obvious answer, based on historical research and evidence for this is, so it's not worth discussing something so blatantly obvious.

Spoiler Alert, click show to read: 

Midget combat

[econ21]

Which makes me wonder why all those armours in museums tend to be very small?

A google search threw up this:

Most of the armor that medieval heights was guessed from was, more often than not, 3/4 scale display armor, made that way to save metal. The reason this smaller armor is so pervasive is because real armor generally did not survive to modern times, if only because it was repeatedly passed on from owner to owner, until it got so outdated or beaten up that it was salvaged for its steel. The few surviving suits of armor of the 'full' size (like the suits that the various King Henrys left in their name in england) demonstrate a height in the same range as modern western men.

But it looks like I got it garbled about medieval warriors being big men. I was thinking of the evidence of the skeletons at Towton, but it turns out they were of mixed heights:

The bodies found from the battle also reveal a broad range of sizes, from one chap who was rather short at around 5'2" or so, to a tall likely looking fellow of 6' or 6'1", so all sizes were obviously present at the battle, and probably fairly representitive of England of the mid-15th Century.

The point I dimly recalled turns out to be that their skeletons show strong men, like professional sportsmen, but not necessarily big ones:

Swinging swords around for hours on end left its mark on the bones of Medieval soldiers. In fact, their right arms resemble those of baseball pitchers, according to researchers at the University of Bradford in the U.K.
Forceful, repetitive movements make bones bend and thicken in response to the stress. So anthropologists Jill Rhodes and Christopher Knusel reasoned that Medieval swordplay should have produced skeletal distortions. They looked at the excavated skeletons of 10 men who had died of sword wounds between the 10th and 16th centuries. The right arms showed changes in shape and thickness similar to those found in professional baseball pitchers, Knusel says. "Swinging a sword is very, very similar [to pitching]. It's an overhead type of motion," he says. The changes weren't seen in nine uninjured male skeletons in the same York cemetery, they reported in last month's American Journal of Physical Anthropology.

The authors also reported on 13 skeletons buried in a mass grave after the Battle of Towton in 1461. These men showed different changes: Their left arms were bent and thickened. Knusel says the skeletons may be the bones of archers who held their powerful longbows with their left arms.

Here's more from the Univeristy of Bradford:

The general size and robusticity of the individuals from Towton is unusual when compared with other medieval populations. Many of these individuals are more robust (stockier) than the medieval norm, appearing similar to modern professional athletes. The physical appearance of these individuals, then, may be related to extended periods of strenuous exertion prior to physiological maturity (i.e. in youth). Among these are numerous SchmorlÕs nodes in the vertebral column (from pressure exerted on the intervertebral discs in heavy lifting), os acromiale of the scapular spine, a condition that is often accompanied by rotator cuff (muscles that stabilise the shoulder) tears, and an avulsion fracture of the humeral medial epicondyle, a condition that develops from throwing (e.g. in projectile use) in more recent juvenile individuals. One hypothesis to explain this pattern is that these individuals were selected as participants in the battle because of previous experience and training in armed combat from a young age. Some support for this relationship comes from a number of healed injuries, testimony to prior involvement in armed conflict.

And to confirm what was said about height falling in the Middle Ages:

A recent study conducted at Ohio State University, based on skeletal data from 30 previous studies, reveals that men living during the 9th to 11th centuries had an average height of about 5 feet 8 inches. Average height then steadily declined until it reached a low point of 5 feet 5.5 inches in the 17th and 18th centuries, rising again through the 19th century and only reaching prior heights in the first half of the 20th century. An article on the study by Richard Steckel appears in the Social Science History journal.