Task-specific measures of balance efficacy, anxiety, and stability and their relationship to clinical balance performance.

The main objective of this research was to investigate the effects of postural threat on performance of three clinical balance tests. Thirty-one healthy young adults performed quiet stance, maximal reach, and one-leg stance tasks at two levels of postural threat, which was modified through the use of a hydraulic lift. Increased postural threat significantly affected postural control measures for both simple and dynamic balance tests. Physiological and state anxiety increased as a result of increased postural threat whereas ratings of perceived stability and balance efficacy were reduced as a function of increased postural threat. Efforts to diagnose balance disorders based on balance performance may be confounded by the influence of psychological factors.