Correct seat height is important. If a chair is too high or the person is sitting on a cushion that has made the chair too high, pressure issues can develop. If the person’s feet cannot reach the floor or their footplates, more pressure is put through the buttocks and legs. Also if a person cannot reach the floor or footplates they often have a tendency to slide forward in the chair, which can cause shearing and poor posture.
Shearing can outweigh pressure as the cause of pressure sores, as it impedes blood flow more easily than compression. This can be likened to bending a hosepipe being more effective than squeezing, to cut off water flow.
The areas of the body vulnerable to shearing are those which support the body when sitting and allow forward slide.
These areas include the ischial tuberosity’s, the V-shaped bone at the bottom of the pelvis that come into contact with the surface when a person is sitting down. Other areas vulnerable to shearing include the heels, elbows and shoulder blades.
Pressure weakens the skin by reducing blood supply to the tissues, and makes it more vulnerable to friction. Pressure and friction acting together quicken the process of skin breakdown.
Seat width is important. If a chair is too narrow it can cause pressure and friction at the hips and side of thighs. If too wide, the person may not sit centrally and sit at an angle causing more pressure through one side. It is important that a person’s weight is distributed as equally as possible.
Correct armrest height is important to enable the person to transfer in and out of the chair, and also assist with repositioning themselves as often as possible in the chair.
Individuals that are able to get out of their bed or chair should be encouraged to do so as regally as possible or when they start feeling uncomfortable.
Encourage individuals that are mobile to change their position every 15 minutes. Off load weight from side to side or a small movement up from the chair. Movements may only need to be small, but may give a significant difference in pressure and comfort.
Where they are unable they will need to be assisted with regular positioning, such as standing, sideways 30 degree tilt, with a hoist or using standing equipment.
If a person is not mobile and they have tilt and space seating in place, us the tilt function to change their position at least hourly. More regularly if possible. Do not let individuals sit in a seat for more than two hours without being repositioned.
Do not leave hoist slings and slide sheets in place unless this has been assessed and recommended by a Health Professional and a Risk Assessment put in place.