...is commonly applied in lameness diagnosis. Vets have expressed various opinions about the point and value of the flexion test. Unfortunately, nobody has so far expressed thoughts on what the more or less severe lameness can then be attributed to. In my opinion, it is important for the horse owner to understand on what principle the test is based, in order to judge the situation and decide whether he wishes to continue using the horse, or is willing to take upon himself the cost of treatment.
The situation is as follows:
It is common knowledge that, when bending the toe joints at a certain place, the blood supply to the hoof is interrupted, so no blood flows into the hoof. If there is a painful inflammation in the hoof, the lack of circulation is comfortable, because it disables sensitivity to pain. Above the "tourniquet" location, in the region of the navicular bone and the head of the pastern, congestion develops. When the limb is released and takes up its normal angle, the blood rushes into the inflamed region with increased force (congestion wave), which is even more painful for the horse than normal circulation.
THUS THE FLEXION TEST GIVES INFORMATION ON WHETHER THERE IS INFLAMMATION IN THE HOOF AREA.
At first one does not know where the inflammation is localised. The specialist can draw conclusions based on the shape of the hoof capsule and the way the horse uses the foot as to whether it is a developing hoof abscess, the beginning of coffin bone rotation, or navicular syndrome. Appropriate measures can, in any case, lead to complete healing, so long as the cause is recognized and eliminated.

With friendly permition by DVM H. Strasser
Copyright 2005 Dr. vet. med. H. Strasser
Ed & Trans. Sabine Kells