Investigation of the posture control during the preparation for voluntary movement

The aim of this study is to examine the two-level control approach regarding the posture control in terms of postural adjustments and muscle forces. Kinetic, kinematic and muscle activation data of 8 male participants were collected. In this regard, the movement protocol for voluntary movement and reaction to the auditory stimulus, the phases of posture control while quiet stance on one foot and preparation for voluntary movements were examined. There was no significant difference between the two-level posture control components, postural adjustments and active-passive muscle forces for protocols. There was no relation between the two-level posture control approach, which is emphasized for representing the supraspinal and spinal levels, and active-passive muscle forces. It is considered that the two-level posture control components represents the whole body control but yet the active-passive muscle forces being limited to the used lower extremity model is an important limitedness. There was no significant statistical relation noted between the behaviors of reciprocal-coactivation and active-passive muscle forces regarding the postural adjustments which considered to be relating to the two-level posture control mechanisms. The two-level control mechanism and postural adjustments within the scope of the findings, it is considered that the postural imbalance is an important factor for the examination of phases of quiet stance and preparation for voluntary movement; that the two-level control mechanism and behaviors of postural adjustments are affected by the same. Additionally, it is believed that it is more convenient to examine the active-passive muscle forces for the posture control through a whole body model. Key Words: Preparation for movement, postural control, two-level posture control mechanism, postural adjustments, active-passive muscle forces