Concurrent Performance of Stroop and Single-Leg Balance Influences Postural Control Under a Dual-Task Paradigm

Though clinical assessments incorporate single-task (ST) paradigms, daily activities integrate cognitive and motor tasks concurrently rather than independently. Therefore, dual-task (DT) paradigms may better reflect overall performance. The purpose of this study was to determine if differences in cognitive and motor performance existed between ST and DT paradigms with two Stroop variations. Eighteen healthy college students (four males, 20.78±1.06 yrs., 168.49±9.10 cm, 63.88±7.90 kg) volunteered. Participants performed two Stroop variations: 1) Stroopsingle: one color-word stimulus presented every two seconds for 48 seconds and 2) Stroopmultiple: 24 color-word stimuli presented simultaneously. The cognitive (Stroop) and motor (single-leg balance) assessments were performed under ST (independently) and DT (concurrently) paradigms on a tri-axial force plate. Participants verbalized the color of the color-word while maintaining postural control. Center of pressure (CoP) speed (cm/s) and time-normalized 95% elliptical sway area (cm2/s) were calculated to quantify postural control. The number of correct congruent and incongruent responses of Stroop were recorded to quantify cognitive performance. Repeated measures one-way ANOVAs were performed for each outcome variable with alpha level set a priori at p≤0.05. No differences in cognitive performance were observed between ST and DT for both Stroop assessments (p>0.05). CoP speed was slower under both DT assessments than under ST (p<0.01). With Stroopmultiple, total sway speed (p<0.01) and sway area (p