influence of postural anxiety on postural reactions to multidirectional surface rotations previous studies have shown significant effects of increased postural anxiety in healthy young individuals when standing quietly or performing voluntary postural tasks however little is known about the influence of anxiety on reactive postural control the present study examined how increased postural anxiety influenced postural reactions to unexpected surface rotations in multiple directions ten healthy young adults mean age 255 yr range 2227 yr were required to recover from unexpected rotations of the support surface 75 degrees amplitude 50 degreess velocity delivered in six different directions while standing in a low postural threat surface height 60 cm above ground or high postural threat surface height 160 cm above ground condition electromyographic data from 12 different postural leg hip and trunk muscles was collected simultaneously full body kinematic data were also used to determine total body center of mass com and segment displacements four distinct changes were observed with increased postural anxiety increased amplitude in balancecorrecting responses 120220 ms in all leg trunk and arm muscles decreased onset latency of deltoid responses reduced magnitude of com displacement and reduced angular displacement of leg pelvis and trunk these observations suggest that changes in dynamic postural responses with increased anxiety are mediated by alterations in neuromuscular control mechanisms and thus may contribute significantly to the pathophysiology of balance deficits associated with aging or neurological disease