Background: The OPTIMAL theory of motor learning identifies motivational (enhanced expectancies, EE, and autonomy support, AS) and attentional (an external attentional focus, EF) factors that affect motor performance and learning [1]. One implication of this theory is that standardized clinical and laboratory assessments of physical capacity and motor performance that do not incorporate optimizing conditions may underestimate true maximal capabilities. The influence of "optimized" conditions on a clinical-applied test of balance control was examined with healthy participants. Given the motor performance benefits of optimized conditions predicted by the OPTIMAL theory, it was hypothesized that providing participants with information that induced EE, provided them with AS, and promoted their use of EF would reduce balance errors and postural sway.
Methods: We used as an exemplar assessment, the Balance Error Scoring System (BESS), and center-of-pressure (COP) velocity measurements of postural sway. Participants performed under two different conditions, separated by two days: an optimized (EE, AS, and EF) condition and a control ("neutral") condition, with sample-wide order counterbalancing. In each condition, participants performed three stances (double-leg, single-leg, and tandem) on two support surfaces (firm and foam). Stance order was participant-determined in the optimized condition and, for the control condition, yoked to a participant in the optimized condition.
Results: Participants committed fewer balance errors in the optimized condition than in the control condition (p < .001) and their resultant COP velocity in the optimized condition was lower than that in the control condition (p = .004). BESS scores were correlated with resultant COP velocity (r = .593, p < .001).
Significance: Our results demonstrated the impact of implementing optimized, as opposed to "neutral" control, conditions for better insight into balance capabilities in normal and challenging situations. Practitioners' roles in mediating test situations and using subtle wording to promote optimized performance may have consequential impacts on motor assessment outcomes.
Keywords: Autonomy support; BESS test; Balance; Enhanced expectancies; External focus of attention; OPTIMAL theory.
Published by Elsevier B.V.