Compensatory mechanisms of balance to the scaling of arm-swing frequency. Issue 14 (5th November 2015)

• Record Type: Journal Article
• Authors: Ko, Ji Hyun; Wang, Zheng; Challis, John H.; Newell, Karl M.
• Is Part Of: Journal of biomechanics. Volume 48:Issue 14(2015)
• Page Start: 3825
• Page End: 3829
• Publication Date: 2015-11-05
• Subjects: M1 mechanism 1 (moving the COP with respect to the vertical projection of the COM) -- M2 mechanism 2 (counter-rotating segments around the whole body COM) -- M3 mechanism 3 (applying an external force other than the ground reaction force) -- COP total whole body center of pressure -- COM1 center of mass determined from M1 -- COMTotal total whole body center of mass -- COMSeg center of mass of a given effector segment -- MA1 displacement of the moment arm determined from M1 -- MA2 displacement of the moment arm determined from M2 -- MATotal displacement of the moment arm determined from M1 and M2; Postural control -- Arm-swing -- Center of mass -- Center of pressure; Animal mechanics -- Periodicals; Biomechanics -- Periodicals; Biomechanics -- Periodicals; Mécanique animale -- Périodiques; Biomécanique -- Périodiques; Electronic journals; 571.4305
• DOI: 10.1016/j.jbiomech.2015.09.008
• Languages: English
• ISSNs: 0021-9290

Abstract

Abstract: The present study investigated the contribution of theHof (2007) mechanism 1 (M1-moving the center of pressure (COP) with respect to the vertical projection of the center of mass (COMTotal )); and mechanism 2 (M2-rotating the trunk and upper limbs around the COMTotal ) to postural control and the stability of COP–COMTotal cophase as a function of lateral arm-swing frequency. Young adults were instructed to stand still on a force platform while alternating their arm swinging from above the head to the side of their thigh to create perturbations to postural control. Scaling the frequency of arm-swing (random step changes of 0.2 Hz within a bandwidth of 0.2 to 1.6 Hz) increased the SD of COP but decreased the SD of COMTotal . Increments in arm-swing frequency induced a progressive increase in M1 and decrease in M2 in terms of their relative contribution to postural stability. The cophase between COP and COMTotal became more tightly in-phase over increments of arm-swing frequency. These findings show an adaptive compensatory role of M1 and M2 within the stability of COP–COMTotal coupling in the regulation of human balance control.