Rezvan Azimi; Behrouz Abdoli; Mohammad Ali Sanjari; Reza Khosrowabadi
Abstract
Introduction: Many studies evaluate the interaction between cognition and posture but the effect of cognitive task difficulty and articulation on postural control remains inconclusive. The purpose of the present study was to examine the interaction effect of cognitive task difficulty and articulation ...
Read More
Introduction: Many studies evaluate the interaction between cognition and posture but the effect of cognitive task difficulty and articulation on postural control remains inconclusive. The purpose of the present study was to examine the interaction effect of cognitive task difficulty and articulation on postural control.Methods: Twenty healthy young volunteers (Mean age 22 ± 2.3 years) performed four random conditions while standing on a force platform. Conditions involved combinations of two level of cognitive task difficulty (easy and difficult cognitivetask) and two level of verbal response (simultaneous and final).Results: Two-way ANOVA (significant level P<0.05) results demonstrated marked increased in the standard deviation and area of 95% confidence ellipse of the center of pressure in the difficult cognitive task condition with simultaneous verbalresponse. (P<0.05). Also, in the final response condition, difficult cognitive task reduced area of 95% confidence ellipse.Conclusion: According to the results of the present research, it seems that the difficult cognitive task requires a greater part of attention capacity; subsequently,attention is withdrawn from the postural task and automatic control regulates posture more efficiently through unconscious, fast, and reflexive processes. Also, postural control is simultaneously affected by the difficulty of cognitive task and articulation.Therefore, for designing appropriate interventions, it seems necessary to pay attention to the interactive effects of the difficulty and articulation of cognitive task.
Ali Farsi; Hadis Kavianpoor
Abstract
The purpose of present study was to determine the effect of different levels of balance task difficulty and visual feedback on balance in elderly women. Fourteen healthy elderly women (mean age 57/65 yr) were selected voluntarily. Participants were asked to stand still on a stability platform under each ...
Read More
The purpose of present study was to determine the effect of different levels of balance task difficulty and visual feedback on balance in elderly women. Fourteen healthy elderly women (mean age 57/65 yr) were selected voluntarily. Participants were asked to stand still on a stability platform under each of two conditions (with visual feedback and without visual feedback) in three levels of difficulty (6, 8, 10). Stability index scores (Overall, Anterior- Posterior and Medial- Lateral) were calculated by Biodex Balance System. Duration of each test was 20 seconds and rest times were 20 seconds. Results showed that with increasing task difficulty, score of Medial- Lateral balance (p= 0/02) increased significantly. In addition, There was a significant reduction in the scores of Overall balance (p= 0/001), anterior - posterior balance (p= 0/01) and medial - lateral balance (p= 0/01) in visual feedback condition compared with without feedback condition. Overall, the results of this study showed that increasing task difficulty increases postural sway and availability of visual feedback can improve balance and reduce the postural sway.
