The Horse Rider's
Stirrup Length
There is no
official rule that refers
directly to the rider's stirrup length, so really it doesn't matter
what stirrup length you have. However you do have to fulfil
the following rules:
-
Thighs and legs
steady and well stretched downwards
-
The
heels the lowest point
If your heel is up, your
stirrup is probably too long.
Here are the current top
4 world & Olympic champions and their stirrup length. Often a
lot shorter than we think!

See see three red dots.
One on the hip, one on the knee and one on the ankle. It's quite
uncanny that all of them ride at the same angle. And,
considering the leg is BENT when the foot is in the stirrup, if you take your
feet OUT of the stirrups, the bottom of the foot must therefore be below the stirrups.
The major texts I have reviewed
have all set the riders stirrup at the same length for dressage (and funnily
enough the same for reining, campdraft & speed games). They all say
for the rider to take their feet out of the stirrup, look up and the stirrup
should sit just underneath the ankle knobble.
For these four top riders, from 3
different countries all to have the same length, probably shorter than you think
is definite evidence that you should really start to copy some of the champions.