We had longe lines as kids, don’t remember using them that much though, as we had no arena. I had basic longeing lessons when I returned to riding, from a h/j coach. And I have had more sophisticated longeing lessons from my current dressage coach, who likes to also longe square and down the long side, moving her feet, and can get a horse to reach over the back and extend the neck in just a rope halter, no gadgets. I am not at her level, but am decent at longeing.
I don’t recall ever having major trouble sorting out the line and whip. I will say that it helps to have a longe line that feels comfortable in your hands. My coach loves an extralong cotton web longe line, but my hands are too small and a bit too weak (arthritis in the finger tips) to handle all that line. So I prefer my nylon web longe line that is on the short side, pretty much maxed out on a 20 metre circle. It is important to always wear gloves, and to have a longe whip that is comfortable in your hand. I once ended up using a buggy whip for a while, didn’t realize that’s what it was, and it was just that least bit too heavy and made my shoulder sore after a while.
As far as longe technique, it is related to working on a rope halter/12 foot rope in groundwork or small circles. If you or your horse are having trouble with the concept, it’s very useful to do small circles walk and trot around you, and progress to doing a 20 metre circle with you walking to the inside.
Anyhow: get equipment that doesn’t give you problems; wear gloves; and don’t feel you need to keep your feet in the middle of the circle at all times.
Now, your horse should not be pulling you around, and you should not be mindlessly moving the center of the circle. But there is no reason you can’t trot your horse on a big square, or jog down the centerline of the arena with the horse on the rail. And no reason why you can’t longe on a 12 foot rope, if you are happy running a smaller diameter circle to keep up.
As far as why longe, I also agree that longeing is not the place to get out the bucks and wiggles. For that, I chase my horse around turnout and let her have a buck n run explosion. I know folks who worry that will cause injuries, but honestly the most chronic stress injuries at our barn develop in horses that never get buck n run turnout but fly around on the longe line, with their head being continually yanked, trying to gallop and buck on a small circle.
Useful things in longeing include a lot of transitions. First, this gets the horse to the point of responding to voice and then hand/body cues. Second, it helps develop balance. No point just flying around in a big trot for 5 minutes.
Another useful thing is teaching shoulder in on the ground, so you can send the horse around first on a small circle and then on a 20 metre circle in shoulder fore/shoulder in. This helps the horse carry himself correctly on the longe line and step under and reach for the (nonexistent!) bit. A horse should be longed in correct bend, not flying around counter bent and inverted. You can accomplish this with just a rope halter, though a longeing cavesson is best, because it tips the nose in (where a rope halter tend to tip it out). You can ask for little flexions to the inside with a longeing cavesson. You don’t need a bitting rig of whatever type to get this done, you just need a few skills. My h/j trainer had me longe in a bit with the line run behind the ears (before our riding lessons, so that might have been for convenience or to teach me the standard format), but my dressage trainer never longes in a bit, just a cavesson (or rope halter if that’s what there), and I think now I would not longe in a bit.
Also watch your own posture and body language in longeing and in all ground work. When we finally got a 20 metre round pen here, I took my mare in at liberty and was impressed that she would go w t c and whoa on voice commands. Then I realized that I didn’t even need voice commands on a good day. I could get her to transition up, down, and halt by mimicking the posture that I used longeing, that is leading arm out to transition up, retracting arm and standing square and up to transition down. Basically if I used my arms and body like I was longeing, but with no line.
However I have never done long lining or ground driving. I can see where it would be useful starting a colt, but I haven’t had that opportunity yet. My coach knows how and has done it, but it isn’t currently a big part of her repetoire.
My coach has taught me a lot of in-hand work, basically getting flexions and lateral work on the ground in a very precise way, in a snaffle bridle.
I also do a lot of “ground work” in a rope halter, which is looser, more “natural horsemanship” based, and for my horse, has evolved into playing with liberty work. I can tell her to go stand on the circus box, and she will walk over and park herself on it. However I still have trouble locking her onto a 20 metre circle in a larger arena, sometimes we get it and sometimes she just wanders off. I’ve worked with other horses that hold a 20 metre circle around you with no line in an arena much more easily, one OTTB last winter that basically got it right away. Longeing with no longe line. I was only doing ground work/in hand with her for my coach, I wasn’t riding her, so I was trying out all kinds of things on the ground with her as she was very green.
Longeing for my own horse has ended up being only a small part of what we do on the ground. At the moment there isn’t much that we need from longeing, other than a day when I don’t ride and want to be sure she gets to move for ten minutes.