Pressure sores: effect of Parkinson's disease and cognitive function on spontaneous movement in bed.

It has previously been shown that the incidence of pressure sores is related inversely to the amount of movement made during the night. The present study of 30 in-patients of geriatric units suggests that the measurement of mean lateral displacement of the centre of gravity may better characterize those at risk than the total amount of movement. The mean displacement was reduced in Parkinson's disease and in dementia. The prevalence of pressure sores was markedly increased where Parkinson's disease and dementia coexisted.