While immobile residents may be at risk of skin injury from sustained pressure, a new study reveals those with limited mobility may be at additional risk because they make unexpected and often unsafe movements.

Researchers from Ireland and six other countries used technology to measure true movement, assessing movement with in-bed sensors and measuring subepidermal moisture to predict pressure injuries as soon as eight days before visible detection.

Categorizing healthy versus unhealthy movements, the team reported that 18.3% of patients found to be “immobile” under Braden criteria were actually highly mobile — and about 13% of those considered “bedfast” were making a high frequency of movements, most of them deemed unsafe, such as dragging the body over bedding surfaces.

“The traditional focus on low movers/immobile individuals may detract from the identification of those making an abnormally high frequency of unsafe movements,” wrote lead researcher Aglecia Moda Vitoriano Budri of the Skin Wounds and Trauma Research Centre at Ireland’s Royal College of Surgeons.