Another last quote from Charles De Kunffy's 'The Ethics and Passions od Dressage'.

"A horse should not be held back by the reins, Horses hindered by the rider's hands cannot engage their haunches properly, will work with discomfort and pain under stress, and throw tantrums. Limiting, inhibiting, stiff, disturbing rein contact will cause pain, not only in the horse's mouth but also throughout his musculature, particularly in the neck muscles. Bad hands and ill-used reins can cause damage and deterioration of the joints in the haunches, showing up in 'rein lameness' of various kinds, or uneven motion of the hind legs".

I have always tried to ride using the reins as little as possible, after buying a former runaway, whom I discovered was completely reliable as long as I left control of speed to him. The only lameness I have ever had in any of my horses, in their long, fairly hard-working lives, was, apart from the odd foot infection, due to laminitis, and none of them were prone to tantrums. That's with four horses, all of whom I had for an average of twenty years.

I have never used the reins as little as I do with these two though, and, reading that, I think I will stick with riding on the weight of the reins only.