Dynamic stability defined for the stability of creature that have four or less num of legs. The stability is solved majorly in dynamic state & responses in terms of motion & overall stability (posture) such as zero moment point (zmp).

Thank you very much. Vikas, how can I define the system that is close or open? For example what kind of system is a human jumping from a place to another and maintaining balance?

Dr. Addie Irawan tahnks. Can you refer me to some paper using ZMP for searching about stability?

I think thesis from MIT or papers such as LittleDog have implement the ZMP. Also you can reference to IEEE trans. robotics for bipedal robot control. Most of the research used ZMP as control reference. Link below (K.Byle, expert publications from MIT) may help you:

http://www.ece.ucsb.edu/~katiebyl/publications.html

Today, our review on gait stability became available online. This review might be of interest for those interested in questions around the topic of "stability" in human movement. The review can be found at:

http://rsif.royalsocietypublishing.org/content/10/83/20120999.full

Accurate synergism and specific or unique recruitment of Muscular system ( Agonist and Antagonist ) in action with the association of the Vestibular system based on the qualitative feedback of kinesthetic perception from the Joints..........

Balance is the product of the Equilibrium but not control of Equilibrium........

A Dynamic stability in Human movement can be a displacement of the body in a (normally upright ) position without an external support and by Accurate synergism and specific or unique recruitment of Muscular system ( Agonist and Antagonist ) in action with the association of the Vestibular system based on the qualitative feedback of kinesthetic perception from the Joints.......

Dynamic movement is a series of short-time intervals of quasi stationary states. The length of these intervals depends on the rapidity with which the movements are carried out.

I think, strictly speaking, stability is a term generally borrowed from control theory. It is generally refereed to Lyapunov stability for linear control system. For nonlinear control system, there are several measures can capture the system stability such as limit cycle.

According to Faye Horak, "Postural orientation involves

the active control of body alignment and tone with respect to

gravity, support surface, visual environment and internal references.

Spatial orientation in postural control is based on the

interpretation of convergent sensory information from somatosensory,

vestibular and visual systems. Postural equilibrium

involves the coordination of sensorimotor strategies to stabilize

the body’s center of mass (CoM) during both self-initiated

and externally triggered disturbances in postural stability."

I tend to think of dynamic stability in the way Horak defines postural equilibrium. "If I have the ability to control my center of mass during movement, I have dynamic stability.