Ability to control postural balance is a prerequisite for standing and gait training during the period of rehabilitation in patients with balance disorder. Precise and quantitative assessment of balance deficit as well as development of effective training methods are the important areas of research in this field.

The purposes of this study are ⸁ to assess the test- retest reliability and clinical feasibility of Computerized Balance Evaluation and Training System(COBETS) developed by Department of Medical Engineering and Department of Rehabilitation Medicine at Chonbuk National University and ⸂ to quantitatively assess the static and dynamic postural control ability of the patients with balance disorders due to various causes using COBETS and compare them with the results of normal control subjects.

The subjects consist of 21 patients with brain damage by stroke, head injury, or surgical procedure to control intractable epilepsy, 5 patients with lower extremity amputation, 6 patients with unilateral total hip replacement, and 50 normal control subjects. Fifteen out of 50 normal control subjects performed subsequent two trials to evaluate the test- retest reliability of the COBETS. There was no statistically significant difference between the results of first and second trials in static and dynamic postural sway measured by COBETS. Therefore, the COBETS is considered to have sufficient test- retest reliability. In the patients with brain damage, amputation, and hip joint replacement, static postural sways during comfortable, narrow, and affected one- leg stance were significantly increased than normal control subjects. Abnormal results in somatosensory evoked potential study and presence of motor weakness were negatively influenced to the results of static postural sway. In all the patients groups, the movement time, path error, and peripheral sway were markedly increased in forward and affected lateral directions compared with normal subjects. Abnormal sensory and motor findings also negatively influenced to some parameters of dynamic postural control. However, there was no difference in the postural sway among the patients groups divided by the causes of balance disorder.

The COBETS is considered as a reliable and clinically useful tool for quantitative assessment of static and dynamic postural control in the patients with balance disorders. Its usefulness for the training of balance control is subject to be defined in future.