Assessments of Balance Control Using Tetra-ataxiametric Posturography

OBJECTIVE: To assess and to compare the balance control between healthy old and young adults using clinical tests and tetra-ataxiametric posturography. METHOD: Eighteen healthy elderly adults over 60 years old and twenty one young individuals under 60 years old were recruited. All subjects had no neurological, cognitive and musculoskeletal problems, and were capable of standing and walking independently. The postural control capabilities of the subjects were assessed using the timed up and go test, Berg balance scale and a Tetrax(R) tetra-ataxiametric posturography (Tetrax, Ramat Gan, and Sunlight Medical, Tel-Aviv, Israel), which utilized two paired force plates measuring vertical pressure fluctuations over both heels and forefeet. Stability index, weight distribution index, synchronization index, and Fourier index were measured at six different head positions and at two positions with standing on pillows, and analyzed by independent t-test. RESULTS: The stability index was higher in the elderly subjects (p<0.05) than in young subjects, which indicated that the ability of balance control in the elderly subjects was poor. The abnormality of peripheral vestibular system, central nervous system and musculoskeletal system all affected the balance control in the elderly subjects, when standing on pillows or turning head to the up, down, right and left sides. However, the weight distribution index and synchronization of both heels and forefeet were not significantly different between the elderly and young subjects. CONCLUSION: These findings suggest that elderly adults have more deficits in postural control than young subjects. Therefore changing environment around elderly adults and educating for prevention of falls were needed.

Comparison of the Spinal Level Assumption by Palpation of the Iliac Crest and Posterior Superior Iliac Spine

OBJECTIVE: To compare the clinical usefulness of the posterior superior iliac spine (PSIS) with that of iliac crest (IC) for identifying the lumbar vertebral level. METHOD: Lumbar spine level was identified by the line connecting bilateral upper margin of iliac crests in the antero-posterior lumbar X-rays of 120 patients. Assumed IC level and assumed PSIS level were compared by 3 examiners' palpation in 60 patients. A marker was taped on assumed IC level and assumed PSIS level by 4 examiners and the postero-anterior lumbar X-rays was taken in randomly distributed 50 patients. RESULTS: IC intersection line was ranged from the L4 spinous process to the L5-S1 interspinous process in all patients. Inter- examiner agreement of palpation was significantly greater in PSIS than IC level (p<0.05). The marker indicating assumed IC level was higher than true IC level in all patients and was higher than L3-4 interspinous process in 8%. CONCLUSION: We may use PSIS level for assumption of the lumbar vertebral level to compensate for the limitation of iliac crest palpation, but at the same time keep in the mind the variarity of the PSIS level.