This blog is in response to a question raised from one of my recent blogs concerning a comment made in my very first Saddle Fit Tip #1 on Saddle Balance. Geoffrey wanted to know more about the stress lines I mentioned right at the beginning of the video. While I can tell you what to look for, I went to my good friend Dr. Joanna Robson, DVM and author of “Recognizing the Horse in Pain and what to do about it” for the physiology behind this.
She said that “the stress line that appears across the shoulder can be totally normal in thin skinned or sensitive horses, especially in summer with the flies. However, repeated triggering of the nerves that innervate the "cutaneous trunci" muscle (the muscle that flicks flies) can create this line as a secondary problem related to pinching from an ill-fitting saddle. The abdominal stress line is also formed from repeated triggering of a negative reflex point over the loin. The horse will hyperextend the topline and contract the muscle (also cutaneous trunci) under the skin and along the external abdominal oblique. This does not result in the “nice” abdominal line you may see in a horse that is correctly engaging its topline and its core.”
I guess this is akin to developing muscle definition in a human as a result of incorrect training, resulting in a look that you don’t want. Apparently there are products available online to counteract the physical appearance of stress lines, but again – here we are treating symptomatically for issues that could be dealt with at their cause. Stress lines can also appear in hooves (just like we have calcium deficiencies that show up in our finger nails), but again – these can be treated at the cause rather than to diminish only the symptom.
Anyway the point is that it’s not called stress line for nothing – obviously something is causing the horse such pain that it results in a physiological change in its appearance. Maybe it’s the saddle?
Jochen Schleese, CMS, CSFT, CEE