Effects of different heel angles in sleep mode on heel interface pressure in the elderly

- Elderly's natural foot postures are in neutral external rotation and upright position.
- Heel suffers greater interface pressure when foot is in an upright posture.
- Age, weight, and BMI do not have correlation with heel interface pressure.
- Pressure-relieving mattress may not be good enough for all pressure ulcer cases.
- Heel skin of elderly is very dry and lack sebum.

BackgroundThe heels are one of the most common sites of pressure ulcers, and the incidence rate in the elderly aged 70 years or older is high. Although there is literature on heel interface pressure, the heel interface pressure of the elderly in different postures has not yet been explored, which will be investigated in this study, as well as the effects of different foot positions. Their skin conditions will also be examined.MethodsTwenty-five females and twenty-six males, 70 years old or older, are evaluated while lying down, with only their naked foot in its natural position on a mattress, as well as placed on a standard or pressure-relieving mattress in different positions. The moisture, sebum content, and elasticity of the skin of the heel are tested.FindingsThe heel of most of the participants is positioned at a 60°-69° or 90°-99° angle to the support surface. The heel interface pressure is the greatest when the foot is upright. The age, weight, and body mass index have no significant impacts. The moisture and sebum content are extremely low while elasticity is normal.InterpretationThe relaxed position of the foot is in neutral external rotation and upright positions. A greater amount of pressure is experienced when the foot is upright. The pressure-relieving mattress is more effective for reducing heel pressure but may not apply to all cases. Finally, the skin of the heel is dry and lacks sebum, which implies greater risk of developing heel sores.