Among various test methods for evaluation of postural control, posturography(PG) using force platform is well known as one of the most quantitative, sensitive and convenient method in normal subjects and in patients with impaired postural control.

The purpose of this study was to obtain the effect of vision and proprioception on postural control in hemiplegic patients, to compare postural control of normal with that of hemiplegic and to get characteristics of postural control in hemiplegic patients.

We recorded the movement of the center of gravity for 45 seconds on force platform in 18 normal control and 16 hemiplegic patients under the conditions of eye-open or eye-closed on the stable surface and on the hard sponge, and processed these data using posturography software to acquire 5 parameters of posturography, i.e. maximal sway(mm), trace length(mm), speed(mm/sec), area(mm²) and its mean radius(mm).

The results were as follows:

1) In hemiplegic patients, visual deprivation only didn't cause any loss of balance and under impaired proprioception the 5 parameters of PG were increased. Both visual and proprioceptive loss, when balance is controlled by only vestibular function, caused the increase of the 5 parameters of PG.

2) Compared with normal control, hemiplegics showed the increase in the maximal sway, mean radius and area, and the decrease in the speed and trace length of PG.

With the results above, postural control of hemiplegic patients were affected more by propriception than by vision and hemiplegic patients showed the impaired postural control compared with normal control.

Keywords :Posturography, Hemiplegics, Postural control