Try the pressure points on your hand with holding, pulsing or rubbing pressure for about a minute.
If you yawned, then your body was letting go to relieve stress.
Letting go (i.e. discharging) is necessary for relieving stress. If your nervous system has trouble letting go, the excess energy gets stored in your body, through holding patterns in the muscles and fascia.
Can't let go of the stress. The stress effects on the body remain long after the event. They show up in physical areas like tight shoulder muscles, a heavy chest or soreness in old injuries to name a few.
Discharge and Your Nervous System
Discharge is a natural process in which the nervous system let's go of energy. Individuals who are better at discharge have fewer bouts of feeling keyed up or restless. And, they have an easier time letting go of things that bother them including muscle tension and stress.
Common Forms of Discharge
They include a good yawn (especially shudder-type yawns), heat, twitches, giggling, and tears.
The nervous system is discharging all the time, even when we're asleep. We notice the discharge process is working only through a sense of decreasing tension in our nerves and muscles.
A nervous system that's not working as it was intended does not discharge its accumulated energies smoothly. In contrast, a healthy nervous system discharges easily and seamlessly.
So for example, if you have a healthy nervous system you will settle down quickly after a stressful experience. You will also be able to relax for extended periods of time without feeling restless.
The above info is from www.MyShrink.com
Next time your horse is having a massage, accupressure or chiropractic alingment - look to see if they are letting go.