A new paradigm for assessing postural stability.

BACKGROUND

The sensory organization test (SOT) is an established and effective method for assessing postural stability and determining fall risk. SOT equilibrium scores are derived from the relationship between an individual's peak sway amplitude and a standard, theoretically-derived normal limits of stability (tLOS). Determining an individual's postural stability and fall risk based on this one-size-fits-all tLOS may overestimate functional equilibrium scores and underestimate fall risk when personal stability limits (pLOS) are reduced.

RESEARCH QUESTION

The purpose of this study is to investigate whether LOS measured from a group of healthy adults is different from the tLOS, and whether SOT equilibrium scores are significantly different when calculated using pLOS versus the standard tLOS.

METHODS

Sixty healthy volunteers were recruited into three age-groups: young (18-39), middle-aged (40-64), and elderly (65-80), with 10 males and 10 females in each age-group. Outcome measures included SOT and LOS. Additional measures o balance perception and functional mobility were obtained including the Activities Balance Confidence (ABC) scale and the timed-up-and-go test (TUG). The tLOS and pLOS were used to calculate standard (tSOT) and personalized (pSOT) equilibrium scores.

RESULTS

The mean pLOS from the group of healthy adults was significantly lower than the tLOS. Consequently, the pSOT equilibrium scores were significantly lower than the standard SOT scores derived using the tLOS.

SIGNIFICANCE

Individual measures of LOS are significantly lower than theoretical estimates of the LOS in healthy adults. This suggests that use of tLOS in the calculation of SOT equilibrium scores often overestimates postural stability and may have implications for the determination of fall risk.