Ageing and balance: the measurement of spontaneous sway by posturography.

Sway was measured by static posturography in 74 healthy subjects. Four age groups were investigated: 20-40, 40-60, 60-70 and over 70 years with equal numbers of males and females in each group. Sway increased linearly with age but was not affected by gender at any age. All age groups were more dependent on proprioception than vision in the maintenance of balance, but when reliable pressoreceptor information was removed, dependence on vision increased. The relative contributions of the sensory systems to balance did not alter with advancing age. The increase in sway demonstrated with normal ageing does not appear due to altered peripheral sensibility. It is more likely that it is due to slowing of central integrative processes.