Phil Armitage wrote:You put Cecil's and Jaye's information together and it makes sense how frog support can relax the pull of the DDFT. I would also add something Dr. Myers shared awhile back on the cause of sidebone. He felt it was due to laminitis. If you consider the lamina is inflamed and painful around the entire hoof capsule it would make sense the addition of frog support would be a good way to relieve pain and relax the DDF muscles. Pain is not only in the toe region of a laminitic horse.
Mr. Armitage,
Perhaps I missed this or just haven't made the connection as of yet. Let me provide my thoughts and then you and/or others can let me know where I am missing the necessary information or connections to arrive at the conclusion that adding frog support decreases 'pressure' on the ddft.
1. First we should clarify the terminology 'pressure' vs. 'tension'. It is my understanding that
tendons are used for applying
tension and as such are intermediaries between muscle heads and bones. Tension itself is simply the manifestation of a pulling force. The chain of events is muscular contraction, tendon tension, bone movement (or at least force in the direction of the attached tendon's tension). The term pressure is descriptive of a pushing and/or pressing force, neither of which are direct functions of the ddft. Again, this is my understanding, but adding frog pressure results in a transmission of that pressure to the overlying digital cushion. The digital cushion disperses that pressure in a multidirectional fashion, however, a modicum of that dispersal is still directed proximally, resulting in increased pressure to the overlying ddft...and to the navicular bursa, navicular bone, coffin joint, etc. So as far as a HB shoe decreasing pressure on the ddft, I don't see how that is possible...unless it is not in contact with the frog and is therefore serving as a protective application, preventing pressure from being applied to the frog.
2. He can correct me if I am wrong here, but I don't think what Jaye was saying indicates decrease in tension of the ddft. Animals tend to avoid pain. There may indeed be compensatory muscle contractions, but I don't believe these contractions lie within the same musculotendinous structure as the one experiencing and/or causing the pain response. Ex. if your calf muscle is injured, you are going to modify your stance and try to maintain motion by exerting greater contraction in other muscle groups so that the role of the calf muscle is reduced in your support and forward motion. Same basic principle in the horse. If the contraction of the ddft is causing pain, the modified static stance and the dynamic 'limp' is indicative of the horse avoiding that pain. If the horse were to increase contraction of a muscle group that was the source of the pain, or whose contraction led to pain elsewhere, this would be counter productive to the healing process and the source of further damage. As such, if my understanding of the above is correct (which it is certainly subject not to be), it would seem to me to be counter productive and counter the utility of the proprioception systems for a horse to increase contraction in the ddft during a laminitic event; whether for stabilization or for motion. If anything, I would think (and again, I may be wrong), that a decrease in the pain response would be inversely correlated with an increase in contraction of the ddft...thus making the horse more comfortable results in an increase of activity/muscular contraction...and the reason bute is often discouraged in the recovery process. Either way, from a mechanical or a neurological perspecitve, I don't see how adding frog 'support' decreases either pressure or tension in the ddft...but I welcome the discussion to the contrary as I have been wrong many, many, many, many...well, you get the picture.