The Hock of your horse would be the equivalent to a heel and Achilles tendon. The muscle just above the hock will be equivalent to a calf muscle.
Many times I visit owners obtaining the hocks injected for swelling and swelling. If you want to know more about back pain in horses then you can hop over to www.equinebloodsolutions.com/
The injection is excellent for reducing the swelling and pain but what about the reason. That is correct the reason why... How about the very low back. The hock problem can lead to strain on the lower back and also the lower spine can place a strain on the hock. Many owners never learn why the hocks continue to become irritated.
The lower back may have subluxations and muscle strain that can cause your horse to push harder from the hock. Occasionally your Vet may inform you it's a confirmation problem together with the job you're requesting of your own horse.
You need to consider it this way... that the hock inflammation is a symptom and also injecting the symptom doesn't repair the cause, ie spraying water onto the smoke sensor rather than the fire someplace else in the home.
The stifle may also have a hand at the modified movement. To add to all this there might even be a lesser cervical [neck] subluxation causing incorrect biomechanics from the backbone and transfer the unnatural weight change of your horse into the hocks.