The Marty Robbins song *[Strawberry Roan][1]* describes the story of a cowboy trying to break an old horse, the eponymous Strawberry Roan (I'm unsure of any connection to the various films of the same name).

There are three verses describing the horse (in negative terms emphasising his age and poor physical condition), and the attempt to ride it (emphasising his wild and untamed temperament), with the middle of the three acting as a transition between the two.

> Down in the horse corral standin' alone<br>
  Is an old caballo, a strawberry roan<br>
His legs are all spavined, he's got pigeon toes<br>
Little pig eyes and a big roman nose<br>
Little pin ears that touched at the tip<br>
A big 44 brand was on his left hip<br>
U-necked and old, with a long, lower jaw<br>
I could see with one eye, he's a regular outlaw<br><br>
I gets the blinds on 'im and it sure is a fright <br>
Next comes the saddle and I screws it down tight<br>
Then I steps on 'im and I raises the blinds<br>
Get outta the way boys, he's gonna unwind<br>
He sure is a frog-walker, he heaves a big sigh<br>
He only lacks wings, for to be on the fly<br>
He turns his old belly right up to the sun<br>
He sure is a sun-fishin', son-of-a-gun<br><br>
He's about the worst bucker I've seen on the range<br>
He'll turn on a nickel and give you some change<br>
He hits on all fours and goes up on high<br>
Leaves me a spinnin' up there in the sky<br>
I turns over twice and I comes back to earth<br>
I lights in a cussin' the day of his birth<br>
I know there are ponies that I cannot ride<br>
There's some of them left, they haven't all died

(Lyrics from LyricFind via google)

I understand, or have been able to look up most of the terms, but the phrase "frog-walker" in the middle verse eludes me. Seeing as it occurs right at the transition, I'm not even entirely whether it's some sort of poor aged gait, or a reference to strong bucking (likening it to a frog jumping). The fact it occurs before a big sigh makes mean lean on the aged angle, but that the immediate next line talks about how near he is to being able to fly pulls me in the other direction.

Is this a known term describing horses (especially during rodeo or initial breaking), and how should it be understood?


  [1]: https://www.youtube.com/watch?v=MJxz2psv5GI