Dynamic balance control
Maintaining, achieving or restoring a state of balance during a dynamic activity is a complex task that requires excellent coordination skills. In fact, unlike in a static position, in a dynamic position the body’s centre of mass moves continuously away from the support base provided by the feet; a person’s ability to control these changes is crucial to prevent falls and increase the body’s proprioception.
The systems that come into play in balance control are the visual, somatosensory and vestibular systems. They operate in a coordinated manner, and if one of the three shows a deficit, this increases the difficulty of maintaining the position. However, these systems can also be trained and are therefore capable of dealing with malfunctions of the other systems.
Dynamic balance can be monitored during routine daily activities such as walking. In this case, Optogait and Gyko provide useful parameters to determine the potential origin of a stability problem and the response mechanism implemented for such a disturbance. The values provided by Gyko reflect those measured in the static or semi-static stability assessment tests, namely the area of movement within which the centre of mass shifts during motion, the average length and angle of the medial-lateral and anteroposterior displacements (see Figure 1).
These parameters can be useful to identify the presence of compensatory movements of the upper limbs when walking, such as the tendency to move the trunk in the medial-lateral or anteroposterior direction. In fact, when pathologies are present, the use of the upper body can play a crucial role in finding and maintaining balance.
With regard to dynamic posture, during stepping, walking and running tests, Optogait also allows asymmetry and the coefficient of variation (i.e. the cost of maintaining a low-effort, symmetrical action) to be measured.
 D. A. Winter, Biomechanics and motor control of human gait: normal, elderly and pathological - 2nd edition, vol. Ed2. 1991.