Popular culture, thanks in large part to the cinematic portrayals has created a perception of martial artists who are able to effortlessly perform fantastic feats of balance and acrobatics.  These much celebrated superhuman attributes, made famous by the "Wuxia" films of Hong Kong and other such genres, are embellished and misleading to say the least.  The ever present Kung- Fu Master standing on one leg perilously over a rocky presipice, or Ninja's sprinting across rooftops, has little to do with practical and veracious combative equilibrium and more to do with entertainment.

Equilibrium is in fact not an all exclusive sense or attribute, instead it is a complex feedback system that consists of two primary categories and a number of sub-categories.
To elucidate, the two types of equilibrium are:

1. "Static Equalibrium" and;

2. "Dynamic Equilibrium".

Static equilibrium is the sense that is responsible for maintaining balance while the organism is not in motion.  The organs that control static balance are located in the vestible of the ear, inside of a membranous labyrinth. The organs are in fact two expanding chambers known as the "Utricle" and the "Saccule."  Each of these chambers contains a tiny structure called "Macula" which are sensory receptors.  
Static balance, while commonly developed by many martial artists by assuming isometric postures for extended periods, is of little or no use in actual combat but is complimentary to dynamic balance.  

Dynamic equilibrium is a sense that manages the balance of the human organism while it is in motion.  The sensory organs that govern dynamic equilibrium are also located in the ear, and are comprised of three "Semi-circular Canals." Suspended within each semicircular canal are "Ampulla" that contain the sensory organs of motion, known as "Crista Ampullaris."  
Dynamic balance is the variety which is pertainent to combat and will be the focal point of this theory.  

Advanced levels of equilibrium and various other forms of proprioceptory cognizance are critical attributes to combat proficiency.  The absense, insufficient or improper development of these senses will hinder the practitioners efficiency and effectiveness in combat.

While all martial artists acknowledge this fact, the training methodogy of the various styles differ significantly both in philosophy and physical practice.  Some arts primary means of developing equilibrium and proprioception are localized poses or individual exercises without extraneous involvement.  
These practices include squatting, standing on 1 leg, slow motion execution of techniques and the striking of air.  Such methods are simply inadequate at developing the full spectrum of combat specific equilibrium necessary for actual fighting.  Whilst these techniques may develop static equilibrium, proprioception and dynamic equilibrium of an abstract,  unopposed nature, said skill does not fall within the scope of combats inherent bilateral constitution.  

The problem with these methods is that they do not address combat holistically, nor do they consider all of its incarnations.
According to the defining conceptual and strategical basis of Muay Sena Combatives, the "Triphasic Theory of Combat," violent physical engagements can be placed in 3 distinct areas of combat:
1. "Standing"
2. "Clinching" and
3. "Ground"
Each phase entails the practitioner striving to maintain an advantageous position. On the ground, position is the name of the game and mastering space is the key. One must understand how equilibrium functions in this unorthodox area of combat. Generally, the top position is superior, certainly if the bottom man is unfamiliar with the ground combat however, all top positions are not equal.  To occupy the top position whilst enwraped in the legs of the opponent, known as the "Guard," permits the bottom man to manipulate the top man's posture and equilibrium, so amongst knowledgeable combatants, the top position in the guard is not a dominant position per se. Nonetheless it does afford access to offensive weapons that are unavailable to the bottom man.  From the perspective of the top man, the objective is retain a top position and advance the positional hierarchy without being toppled over and losing the position so that once a stable and dominant position is achieved, corresponding offensive bodily force may be efficiently and effectively applied.
The success of the top man in doing so is contingent upon a number of factors, however, equilibrium of a very specific variety is paramount, without this top ground specific skill and equilibrium, the position will be quickly lost.  The top man must have a practical understanding of the action-reaction principle and the biomechanical capacities of self and adversary in each position, angles and dead angles, and base. All of these are effected by equalibrium. From the bottom position, equilibrium is very different, but closely related. Here the bottom fighters primary objective is to "sweep" or reverse the top man to commandeer the top position, escape an inferior position and reestablish a guard, attack, or apply subterfugal attacks to facilitate any of the various transistory or offensive techniques.
All of these involve dirupting the equilibrium in some fashion and also require equilibrium to execute in many cases.  On the ground equilibrium is intrinsically linked to weight distribution and the limbs that post on the ground for purchase.

"Terraception" is integral to ground phase equilibrium, as are proprioception and "Extraneocorporalception". The ground requires the most complex and specialized variety of equilibrium and as with the other phases, this sensory development is impossible without extensive training with a semi or none cooperative partner.

Combat equilibrium is an all-encompassing, multi-faceted collection of senses, all of which fall under the dynamic category. It involves awareness of self (proprioception), the opponent (extraneocorporalception), and the earth itself (terraception) and the role gravity plays in these interactions.
This is cultivated not with abstract localized static postures, balancing acts or activities that are unrelated to actual combat, but rather by hollistically addressing each and every phase of combat and the intricacies of each in a realistic manner. The unmitigated equilibrium of all-out triphasic combat consists of proficiency in all of the incarnations of combat and the ability to seamlessly transition between all three phases and within each.  Combat Equilibrium is a mandatory attribute for any Martial Artist, however it must not be a limited equilibrium that only is developed for the practitioners particularly predilections.
Combat is rarely an affair that can be predictably managed, therefore the intelligent fighter must be trained and skilled and all phases. Equilibrium is the foundation to this universal prowess and in unbridged combat.