Part 3: Internal Resistance

In the fit horse, it is internal resistance that limits performance. In the horse being conditioned, resistance limits the potential for strength as well as increases the possibility of muscle injury.

Muscle tightening is the natural physiological response to trauma, be it from a blow or some form of overuse. This will initially show itself as an area sore to pressure or touch, along with a restriction in range of motion. A muscle spasm will also likely occur.A spasm is defined as a bunch of fibers unable to secure their own release, commonly perceived as a knot of tissue. As the muscle in question is asked to release to allow movement, additional effort is required to overcome the tightness. Continued use of this muscle pair will cause increased spasming and pain, eventually leading the potential for a muscle tear.

Proprioception is a fancy term for coordination. Muscle tightening will affect proprioception and quality of movement ascertain muscles are called upon to compensate for weakness, tightness, or soreness in other areas. It is common to find that a horse who is off in one hind quarter is also tight in the opposite shoulder. Synchronization suffers when a horse must overcome the resistance of a tight muscle.

Often on old injury to a foreleg will cause splinting on the shoulder muscles of that quarter. Splinting is a process where a muscle group will tighten in response to an injury by restricting the movement of a joint or body part. Long after the initial injury is healed, the muscles can remain tight and set the stage for loss of proprioception and risk of further injury.