The animal nervous system is one of the most notable changes in the equine with dysfunctional feet loading.
Therefore, farriers and the wider equine community must understand that the animal's nervous system regulates all bodily functions, allowing perceived changes within its alignment through proprioception and other forms of neural feedback.
Acknowledging that the neurological system forms a considerable part of the balance of the equine foot (i.e., that it is not just the external balance of the solar border of the feet) opens avenues of treatment via the diagnostic process. While the horse must stand on the ground surface of its feet, balance is a complex interplay of neuroplasticity throughout the animal's entire body. Therefore, we need to integrate the neural responses of the animal into our diagnostic process when making decisions and devising a treatment strategy or medical intervention, such as trimming or shoeing the equine foot.
Trimming or shoeing the equine foot will cause a change in the biomechanics and musculoskeletal alignment of the upper body, affecting all aspects of limb and hoof flight. Altered orthopaedic balance or biomechanical compensation places stress on the internal structures of the foot and subsequent effects on the neurological system.
After trimming an individual foot and placing it back on the ground, any neurological response you can observe needs to be considered. For example, changes in behaviour or mental status. Positive indications include relaxation, improved breathing, and reduced tension, as these positive indications show that the horse is responding positively to the trimming.
As well as observing the positive responses, you should monitor any changes in the horse's body to ensure the animal is not suffering from complications. Keys to look for are any indicators of compromises in the nervous system, and postural instability, such as neck/head carriage changes, the tension in the upper torso and unwellness to standing still or not wanting to load the individual foot just trimmed. It is essential to observe the distal tendons and ligament tension. The closer you can observe the pathology changes to the distal limb, the more precise the indication of foot imbalance and the biological loading of the distal Interphalangeal joint of the individual limbs.
As there are long-term effects of stiffness and a degree of sensitivity that remain after trauma in the upper torso of the horse, which could be the consequence of past problematic issues, it is pivotal to ensure your intervention does not trigger other unresolved puzzles. Posture and conformation issues will cause coordination issues along with the tenderness of the leg muscles, discomfort, and flexibility of the spinal column of the back that should return to some normality after the trimming process. However, the tenderness of the system's neuromuscular response can take a few days to reduce to a level where the problematic issues can subside. In most of the cases I work with, I gave a time frame of between three days to two weeks for the animal to resolve the degree of sensitivity in the upper torso and the problematic consequences of their dysfunctional orthopaedic stance. If the sensitivity issues still exist after this time frame, I have the horse return for a recheck of the issues and analyse the changing pathology marks throughout their body.
The protective postural compensation is evident in a "ewe neck" posture, changes in the shoulders, shortness of stride and immobility of the rib cage, for example. The consequences of the abnormal tension in the muscles of the shoulder and thoracic regions have a destabilising effect on the loading of the distal interphalangeal joint. Muscle tension around the withers triggers the animal's mid-back to drop and tighten, contributing to the disengagement of the hindquarters, overloading the hind feet and unresolved saddle fitting issues.
Through the trimming process, as the animal responds and adapts to the newly balanced foot, the biomechanical loading of the distal limb's changes will affect their orthopaedic stance or posture. After trimming the foot, the animal's proprioceptors and limb orientation must coordinate postural stance and locomotion by altering the neural fibres in that area, changing the peripheral nerve signals to the muscles involved and then the interaction of the gravitational forces on its body.
This change in the neural pathway can have wide-reaching implications for other body regions. This effect is seen daily in horses with a foot imbalance. If we leave the imbalance in place or intervene and change the hoof balance by trimming or shoeing, we can observe that the animal feels a neural response elsewhere in the body.
In my next blog, part 3, we will continue to explore the articulation of the Distal Interphalangeal Joint on the palmar section of the equine foot.
Comments