Low Air Loss Therapy with Alternating Pressure or Lateral Rotation. Three therapeutic modalities in one mattress. Low air loss (LAL) removes excess moisture and prevents tissue damage from maceration. Alternating pressure is an active therapy causing reperfusion of blood to the skin which promotes healing of damaged skin. Lateral rotation therapy has many therapeutic benefits. Skin breakdown occurs most often because of constant pressure over a prolonged period of time. Most of us shift our weight, stand or turn over through the night but when we suffer from reduced mobility we lay or sit in one position, over time skin often becomes damaged. Repositioning is vital for good skin and also increases fluid movement within the body which can lesson upper respiratory infections, increase circulation and improve bowel and bladder functions.