Patients with schizophrenia commonly show deficits in executive functioning that allow a person to make plans, solve problems, do many tasks simultaneously and adapt to unexpected conditions. Executive dysfunction is associated with very simple and automatic activities, such as walking in schizophrenia patients. However, no study exists about its relation to postural control in these patients.

To investigate the effect of executive functioning on postural control using dual task paradigms.

Fifteen clinically stable schizophrenia outpatients and 15 healthy controls were enrolled in the study. Postural control was assessed with bilateral stance test using the Balance Master system under three different conditions with eyes open and eyes closed (EC): without a task, during a cognitive task (verbal fluency) and during a motor task (holding a cup of water).

Standing on a foam surface with EC resulted in higher postural sway velocities in schizophrenia patients under all conditions (P=0.009, P=0.032, P=0.013). During a cognitive task, both schizophrenia patients and healthy controls showed higher velocities on firm surface with EC in comparison to the condition without a task (P=0.023). Both schizophrenia patients and healthy controls did not show higher postural sway velocities during the motor task.

The effect of verbal fluency on postural sway shows the relationship between executive functioning and postural control in schizophrenia patients. Foam surface also higher postural sway velocities in schizophrenia patients in EC condition suggesting the difficulties in integrating the proprioceptive information in the absence of visual input.