Why do I keep my hands open rather than closing them on the lead? The heading of this post is a partial answer - due to the way our bodies and nervous systems work, an open hand can close more quickly than a closed hand can open - contracting a muscle occurs faster than you can relax a tightly contracted muscle and then engage the opposing muscle to open your hand. So say the horse spooks while I'm leading - I have lots of options - I can close my hand on the lead, I can let the rope slide through my hand - without getting a rope burn which is what happens when a rope gets pulled through your hand when your hand is closed - and I can move my hand to a different position on the rope - all without having to deal with the clenched hand as a starting point.
The other reason I don't use a closed hand on the lead is that it is a brace, and a brace isn't soft. I get a lot of information through the feel of the rope about what the horse is doing and thinking, even though with a horse behind me I can't see the horse, because my hand is soft. It's hard to feel anything through a clenched hand and arm. I really try - not always successfully - to have all my interactions with the horse be as soft as possible - I don't think I can expect my horses to be soft if I'm not soft myself. It's easier for the horse to be soft if I'm soft. But soft can also be declarative - I try to be really clear about what I want and follow through - soft isn't about letting your horse walk all over you or being wishy-washy. Soft can also be big when necessary - although if you're soft you can often accomplish what you want with much smaller movements and cues.
Softness is about attention. One of the most powerful things I'm always learning is that if there is softness in my body, I can more effectively pay attention to the horse and the conversation we're having, because the lines of communication between the horse and me are open in both directions. If I'm braced, I can't hear or communicate as well.
Softness is both physical and mental, and is about being aware of braces and working to eliminate them. As with my leading example, a body held with softness can more effectively keep riding if something happens - say a spook. If you're braced, by gripping with your knees or legs, or if you're carrying braciness in your pelvis or back, if your horse spins, bolts or spooks you are much more likely to come off, because your reaction time is slowed - you've got to undo all those clenched muscles before you can adjust to the horse's motion and begin to influence it - and because being braced tends to push you up off the horse's back. If you can stay soft in your body and continue riding through whatever motion the horse serves up - being "with" the horse and its motion - you've got a much better chance of staying on and being effective. If you brace up and stop riding, you may be dead meat, and you're likely at the least to increase your horse's level of tension/fear.
Bracing can also be the result of emotions we carry - there's a strong connection between fear, and other strong emotions like anger or frustration, and physical bracing. I think that is one reason it takes a while for beginning riders to start to develop an independent seat, leg and hands is that they're anxious and the anxiety expresses itself in braces in their bodies. I also think many horses "read" braciness in us as cause for alarm - think about a horse's "on full alert" posture - head and neck high and tight and entire body tensed - they think when we're braced, we're worried about something and maybe they should be too.
Softness is about breathing. If you aren't soft in your body and posture - and I don't mean soft like floppy I mean soft like unbraced and with a posture that is competent and relaxed and ready to move - you can't breathe deeply and effectively. If you can't breathe effectively your muscles and brain aren't as well oxygenated as they can be, which means that your thinking isn't as clear as it could be and your body won't respond as well.
Softness is about body awareness. Modern humans, being creatures of language and with the ceaseless background chatter they have in their minds - I always think of it as like the distracting scroll across the bottom of a TV screen, but even worse - have a hard time really paying attention to their bodies or anything else - we find it difficult to be truly aware and "there". I work all the time, all day long, even when I'm not with horses, on noticing and eliminating braces in my body, in how I walk and hold myself. When on the horse, a brace can be gripping with your legs, or not allowing your pelvis and back to move appropriately - think bouncing at the sitting trot. A brace can be forcing your heels down, locking your elbows and shoulders (the closed hand on the reins when riding with contact can still communicate softness if the arms, shoulders and back are soft), or clenching your jaw and neck muscles - we can brace with almost any muscle in our bodies. And when we brace, we both interrupt the communication to and from the horse, and we also impede the horse's ability to move freely while carrying us. If we have a habitual brace in our bodies, our horses, in order to adjust to us, will often develop a corresponding brace in their own bodies.
One of the most common braces is the one that's set up when the horse gets heavy on your hands - this is two-party transaction where the horse is pulling on you and you're resisting the pull by bracing, or vice versa - it's a brace with two ends. If your horse is pulling on you, or is heavy in your hand, you're a contributor to the brace. Learning to eliminate this brace and effectively influence your horse's posture and carriage without bracing - with a goal of the horse developing true self-carriage - is a really big thing and one that I'm always working on. But I think the first step on the road is awareness that there is a brace, and that you're part of it.
And braces can be mental - this is the really hard stuff, even harder than the physical things. To my mind, anger is a brace. Resentment is a brace. Fear is a brace. Impatience is a brace. Rigidity of thought and lack of openness is a brace. Letting the ends justify the means is a brace. I could go on, and I'm sure each of us has our own package of mental braces. The mental and physical stuff flow back and forth and influence one another. That's one reason I work so much with my horses on self-calming and the development of trust - if they feel better on the inside they are less braced and reactive on the outside. And a horse that can learn to carry its body with softness, from the inside, will feel better as well. I think it works the same way for us. It isn't just about the technique or the mechanics.
None of this is easy or quick to achieve, and at least for me, it's going to be a lifelong journey, a lifelong practice.