If you are referring to the noseband of a lunging cavesson, then side reins are attached to the bit. I use them looser with a rider than I do without a rider.
Equiband.
You can use it to develop top line and engagement when you ride, you can use it on the lunge, and I actually can’t envision a way it would hurt the horse or the kids to have it on during lessons. (Once he’s acclimated to it, of course.)
It is meant to be used at all gaits and over poles and cavaletti.
Interesting… do you have any links to share on this? I spend most of my learning time on horse movement patterns/dysfunction, but can’t help to get hooked into the human side too.
To keep this on topic for the OP… Er. Nothing can replace being ridden to engage the hind end and core. However, in this case a “gadget” on the head end might help prevent him from going around hollow, all the time. If you decide to go that route, make sure it is adjusted generously and give plenty of breaks (and I mean actually unsnapping whatever it is and letting the horse go freely for a bit.
This is a good one to start with. If you Google quad dominance & knee pain, you’ll find a more on the connection (rounded shoulders & spinal kyphosis are a common cause of quad dominance.)
After OP’s post detailing the horse’s schedule, I personally feel the biggest issue is the horse simply isn’t getting the level of conditioning work needed for an older horse to maintain its fitness level. An older dressage horse whose primary exercise is packing beginners at a walk for 30 minutes 3-4 times a week is not going to be able to maintain the fitness needed to be able to track the hind end up & under. No more than you or I could maintain an easy 150 lbs deadlift by slinging those rinky dink pink rubber coated 3.5 lbs dumbells they have at a Curves gym.
The thing that really doesn’t sit well for me (& frankly makes me tempted to smack OP’s vet ) is that the vet, like most riders, severely underestimates the degree of soft tissue asymmetry in the average rider’s body. And how that in turn leads to asymmetry in the horse after 100s of hours of compensating. Most riders have no clue they have a problem & it isn’t just beginners. In the last few weeks aIone I watched two high level hunter trainers collapse into their right hip/SI asking for a halt after a jump. Right shoulder/cervical & lumbar spine rounding; right hip, sitz bone & leg contracting up; left sidebody bulging out. Spoiler alert: their horses didn’t halt square, straight, or balanced. No surprise there. The horse might try, but it is not physically possible for him. And yet, we riders & trainers are going to insist that the horse try. And what do you think happens to the horse’s body after 100 such halts? A 1000? 10,000?
Next, add in the infinite # of skeletal variances between individual horses. For ease of comparison, let’s look at this phenomenon in humans. As a yoga teacher, I do not offer hands on adjustments to students. Not even pre-Covid. Why? Because it is too easy to injure someone by over-adjusting them into a range of motion that their individual skeletal variances do not allow: I.e., people with a prominent acromion process typically cannot bring their raised arms back far enough to come into line with their ears. If I have my class doing Arda Chandrasana & adjust a student with a prominent acromion by squeezing their raised arms up & back, I’m grating the bursa between two bones & doing some mean things to the muscles & ligaments in the rotator cuff. Over time, that soft tissue is going to break down, adding instability to what is already the least congruent joint in the human body & leading to a lot of pain & inflammation.
At least people can go, “Ow, hey, my arms don’t move that way!” Short of behaviors like bucking which lot of horses won’t do for fear of punishment, the horse has no way of telling me a forced stretch hurts. The horse is hollowing his back because he’s struggling to carry an unbalanced beginner. Get down on your hands & knees, grab a kid to sit on your back (bonus points if your kids are bigger than you like mine are) and instruct them to slide, bounce around, & lean forward as you start to crawl. (There was a study done maybe 2 or 3 years ago that measured the degree to which beginners lean forward compared to a decent advanced rider. Double digit difference. I’ll link to it once I find it.) Now, instruct your child to push down on your head while you try to lift thru your back. Chances are, you won’t be able to unless you are strong & well-conditioned. More likely you’ll find yourself leaning out & stiffening to brace your neck up against the downward pressure in attempt to avoid falling onto your face as your tailbone involuntarily rises.Tell kiddo to push down harder while you keep crawling. Feel any pain your wrists or shoulders? Think it might cause some soft tissue strains & sprains if it goes on long enough? I do. And remember that while the shoulder is the least congruent joint in the human body, we aren’t meant to bear weight on our hands. A horse IS meant to bear weight on his “hands” AND a shoulder joint designed to allow crazy mobility. And he needs conditioning help from humans to develop & maintain the muscular strength to stabilize the joint.
Yeah, you can adjust things to be loose. But what is it even doing? The muscles have to fire in a specific order for a healthy, sustainable movement patterning. These types of aids interrupt that patterning, no matter how loose because the horse has to change his movements to react to them. A certain base level of strength has to be there to avoid injury, & it isn’t. Human example - I hate those headstand frames that are designed to help you invert without bearing weight on your hands. Trouble is you can’t hack an inversion. To get into a “safe” headstand (I’d argue there is no such thing) you must activate thru across the back, chest, & shoulders by pressing into the ground & have the core stability to lift your hips over your shoulders. The headstand frame lets you “headstand” without possessing any of the muscular pre-reqs necessary to avoid injury. Most of the aids the vet suggested are doing the same with the horse; creating a movement without those muscular pre-reqs that help avoid injury.
Realistically, self-carriage for the horse is a precise balancing of kinetic energy that requires self-carriage from the rider. Seems like no one ever wants to admit this because it takes time & requires the human putting in some real work both on & off the horse. Walk & walk/trot beginners aren’t there yet. If this horse is to maintain fitness, it is going to take a decent rider getting on him & several times a week. No shortcuts, no hacks, no work arounds.