Pressure sores — also called pressure injuries or decubitus ulcers — are often associated with hospitals and aged care. But they can begin forming in any person who sits on the same surface for hours without adequate pressure distribution.
The good news: early-stage pressure injuries are almost entirely preventable. The key is understanding what causes them — and acting before the skin shows any signs.
What Causes Pressure Sores When Sitting
Pressure sores form when sustained mechanical pressure cuts off blood supply to soft tissue. The tissue is starved of oxygen and begins to break down — starting from the deepest layers closest to bone and working outward.
This is why pressure sores can be deceptive. By the time you see redness on the skin surface, significant damage may have already occurred in the deeper tissue layers beneath.
When you sit, the areas most at risk are:
- Ischial tuberosities (sit bones) — the primary load-bearing points in seated positions
- Coccyx (tailbone) — particularly in reclined or low-chair positions
- Sacrum — especially when seated in a slumped or semi-reclined position
- Greater trochanters (outer hip bones) — when sitting with legs slightly apart on a firm surface
Who Is At Highest Risk
While pressure sores from sitting can affect anyone, risk is significantly elevated for:
- Full-time wheelchair users who cannot reposition independently
- Post-surgical patients spending extended hours sitting during recovery
- Elderly individuals with reduced skin integrity and limited mobility
- People with reduced sensation (including some neurological conditions) who may not feel the warning signs of pressure
- Desk workers spending 8+ hours daily in seated positions without repositioning
Medical note: If you or someone in your care has an existing pressure sore, this is a medical concern requiring professional assessment. A GP, nurse, or occupational therapist should be consulted. This article covers prevention for people at risk — not treatment for existing injuries.
The 4 Pillars of Pressure Sore Prevention When Sitting
1. Regular Repositioning
The most effective single intervention for pressure sore prevention is repositioning — shifting weight away from at-risk areas before tissue damage accumulates. For wheelchair users, clinical guidelines typically recommend repositioning every 15–30 minutes. For desk workers, standing or shifting position every 30–45 minutes is a reasonable target.
2. Pressure Distribution at the Surface
How your weight is distributed across your seating surface directly determines which tissue areas are at risk. A surface that concentrates load at bony prominences creates high localised pressure. A surface that distributes load across a broader area reduces peak pressure at any single point.
This is where seating surface choice matters enormously — not just for comfort, but for genuine injury prevention.
3. Skin Moisture Management
Moisture (from perspiration) softens and weakens skin, increasing its vulnerability to pressure damage. Seating surfaces that trap heat and moisture accelerate this softening. Breathable surfaces that allow air circulation help maintain skin integrity throughout the day.
4. Nutrition and Hydration
Healthy skin has better resistance to pressure injury. Adequate protein, hydration, and micronutrients (particularly zinc and vitamin C) support skin integrity. This is especially important for older adults or anyone recovering from illness or surgery.
Why Standard Foam Cushions Fall Short For Prevention
Most seat cushions — including many marketed as "pressure relief" products — use foam that compresses under sustained load. Within an hour or two of continuous sitting, the foam beneath your sit bones has compressed significantly, reducing its ability to distribute pressure.
Memory foam compounds this problem by retaining heat. Heat increases skin fragility and accelerates foam compression. The result is a cushion that provides excellent initial comfort but diminishing protection as the hours pass.
For genuine pressure sore prevention, what matters isn't how a cushion feels for the first 20 minutes — it's how it performs at hour three, four, and six.
How TPE Honeycomb Provides More Consistent Protection
TPE honeycomb distributes pressure through a structural lattice rather than through foam compression. Each cell in the lattice deflects slightly under load, sharing pressure with adjacent cells. The geometry means that pressure can never fully concentrate at a single point — it is always being redistributed laterally through the structure.
Crucially, the mechanism is mechanical, not material. Unlike foam, TPE doesn't lose its pressure-distributing function under sustained load. The lattice springs back during use in a way that foam cannot — it maintains its structural depth at hour six the same way it does at hour one.
The open-lattice structure also means continuous airflow across the seating surface. There's no heat build-up, no moisture trapping. Skin that stays cool and dry is significantly more resistant to pressure damage.
→ Read our full guide for wheelchair users and higher-risk individuals
→ See our complete pressure relief cushion guide
Frequently Asked Questions
How quickly can a pressure sore form?
In high-risk individuals — limited mobility, compromised circulation, reduced sensation — early tissue damage can begin within one to two hours of sustained unrelieved pressure. In healthy adults with normal mobility, the timeline is longer. But repeated daily exposure to inadequate sitting surfaces can cause cumulative tissue fatigue over weeks and months.
What does Stage 1 pressure damage look like?
Stage 1 pressure injury typically presents as a localised area of redness that does not blanch (turn white) when pressed. The skin is intact. For people with darker skin tones, discolouration, warmth, firmness, or pain in the area may be indicators. Any suspected Stage 1 pressure injury should be assessed by a healthcare professional.
Can I prevent pressure sores with a donut cushion?
Donut-shaped or ring cushions are generally not recommended for pressure sore prevention. They concentrate pressure at the inner edges of the ring, reduce blood flow to the central area, and are associated with worsening rather than preventing pressure injury. Clinically recommended approaches focus on broad pressure distribution, not pressure removal through cutouts.
Is the Ergo Sleep™ cushion suitable for someone who already has a pressure sore?
If you have an existing pressure sore, please consult a GP, nurse, or occupational therapist before using any seating product. A properly assessed seating system is important for active wound management. The Ergo Sleep™ cushion is designed for general comfort and prevention, not clinical wound care.
How do I clean a TPE honeycomb cushion?
TPE honeycomb can be wiped down with a damp cloth or mild cleaning solution. The open lattice structure makes it easy to clean and dry quickly — a meaningful advantage over foam cushions, which can harbour moisture within the material and are difficult to fully dry.
Does sitting on a hard surface increase pressure sore risk compared to a soft couch?
Very firm surfaces distribute pressure evenly but offer no contouring to bony areas. Very soft surfaces allow sinking that concentrates load at the deepest contact points — usually the coccyx and sacrum. Optimal support sits between these extremes: firm enough to distribute load broadly, with enough give to prevent high concentration at bony prominences.
How often should I reposition for pressure sore prevention?
General guidance for desk workers is to stand or shift position every 30–45 minutes. For wheelchair users, a clinically supervised repositioning schedule — often every 15–30 minutes — is typically recommended. If you're supporting someone with significant mobility limitations, an occupational therapist can advise on the appropriate schedule.
Do air-cell cushions like ROHO work better than TPE for pressure sore prevention?
Clinical-grade air-cell cushions are specifically designed for high-risk pressure injury management and are typically prescribed by occupational therapists for wheelchair users with complex needs. TPE honeycomb cushions are appropriate for general comfort and prevention in ambulatory individuals or lower-risk seated users. If your risk profile is high, please consult a professional rather than relying solely on an over-the-counter product.
Ergo Sleep™ TPE Honeycomb Seat Cushion
Consistent pressure distribution — all day, every day.
Sitting Cushion — $59 + Back Cushion Bundle — $99Free shipping Australia-wide. Always consult a healthcare professional for existing pressure injuries or high-risk conditions.