Centre of gravity represents the point where the net force of gravity of all the body parts is applied. Balance is a specific state of the postural control system, being a vertical orientation of human body maintained through balancing the forces and moments of forces that act on the body. Stability is understood to mean the ability to recover the state of balance and typical body position in the space.
The concept of division of the rider's posture into 5 blocks that has been used in the literature seems to be legitimate. However, due to the natural shape of spinal curvature, the division of body into opposing truncated pyramids (a trapezoid in the sagittal plane and a rectangle with longer horizontal sides in the frontal plane) appears to be more accurate. The eight-segment model is dynamic and illustrates all the shallowed or deepened spinal curvatures very well while maintaining alternate sagittal curvatures with regard to the deficits of motion in the joints. It is also correct in anatomical terms since it contains all the sections and joints in the kinematic chain.
Body posture, considered under conditions of the equestrian pair (a rider and a horse) as a motor task, will be adjusted using the continuous control. This control works within the tracking system and consistently adjusts the activity of different muscles to current needs. These needs result from a specific program encoded in the central nervous system and, more specifically, from the difference between the program and current state of the equestrian pair. This program is developed during equestrian training and it represents a demanded situation.