Reliability of foam posturography in assessment of postural balance in the patients with vertigo

The postural balance is a important aspect of assessment in vestibular rehabilitation therapy.As the computerized dynamic posturography,the foam posturo-graphy performed by using foam in posturography is a useful measurement tool for postural balance.Then,the reliability of foam posturography is critical in clinic.To our knowledge,there is no report about the test-retest reliability of foam posturography in the patients with ver-tigo in China.The foam posturography was taken on the patients with vertigo in stable state and repeated in 3 to 5 days.In the two assessments of test and retest,all subjects stood under 4 sensory conditions,such as firm surface with eyes open(T1),firm surface with eyes closed(T2),foam surface with eyes open(T3)and foam surface with eyes closed(T4)for 30 seconds respectively.The average sway velocity(SV)of center of pressure(COP)under feet of upright standing was recorded as research parameter.The results of patients with vertigo were compared with those of normal subjects.It demonstrated that all normal subjects did not fall in the two assessments.There were 10 of 34 patients with vertigo at least fell one time during the two assessments,and the SVs of these subjects did not taken the analysis of test-retest reliability.The results showed that:(1)The interclass correlation coefficients(ICC)of all 49 subjects including normal subjects and patients without falling were 0.887–0.973 according to the T1–T4 between two assessment.(2)The SVs between the normal subjects and patients were significantly differ-ent in the T2(t 52.018,P 50.049)and T4(t 53.905,P,0.001)in the first assessment and in the T4(t 53.715,P 50.001)in the second.And(3)the cases of falling between two assessments were not significant different(x250.073,P 50.787)in the patients with vertigo.It is concluded from this study that the foam posturography has high test-retest reliability to assess the postural bal-ance in the patients with vertigo in stable state,indicating the foam posturography can be used as the valid means to assess the improvement of postural balance for patients with vertigo in the vestibular rehabilitation therapy.