What a Prophylactic Dressing Can and Cannot Do for a Heel

29 Sept

There is a thread on an American nurses' forum with a four-word title: "To mepilex or not?" The nurse who started it described an arrangement many wards will recognise. Once a patient's risk score crossed a threshold, foam dressings went onto the sacrum and both heels more or less automatically, and nobody had ever explained when a dressing earns its place and when turning would do. One reply answered in four words of its own: "No dressing prevents pressure."

The thread is American, but the question is not. I've spent more than thirty years supplying devices that float the heel, so you might expect me to side with that reply. I don't, entirely. A dressing and a floating heel do different jobs, and the formal evidence for each is thinner than either camp tends to admit.

Put plainly we can say that a dressing changes the surface. Offloading changes the load.

What a dressing on a heel is actually doing

A heel resting on a mattress is loaded in two ways. The weight of the leg presses it down, and whenever the patient slides or is moved, the skin is held by friction while the bone moves on, which shears the tissue in between. I have described both at length in Pressure and Shear: What the Words Mean, and Why Living Tissue Makes It Complicated.

A prophylactic dressing works at the interface, where the heel meets the bed. A multilayer foam dressing adds a little cushioning, and its layers can slide over one another, absorbing part of the shear before it reaches the skin. What it cannot do is make the leg lighter. The heel carries the same weight with the dressing on as without it.

Moisture is where this becomes interesting, and where I need to square something I wrote earlier. In the pressure and shear article I said that moist skin grips hospital fabric harder, not less: in a study of forearm skin against a hospital textile, friction rose by about 26 per cent in men and 43 per cent in women between very dry and normally moist skin. A 2026 computer model of one dressing reports the opposite trend. Its skin-contact layer, a gelling fibre, became far more slippery when moist, and the coefficient of friction against skin fell from 1.55 to 0.22.

Both are true. Friction belongs to a pair of surfaces, not to skin alone. Damp skin against cotton grips; damp skin against a gelling layer slides. The outer film of that dressing, which is what actually meets the sheet, measured 0.33 against cotton. This is why dressing materials are not interchangeable.

KEY POINT: A dressing works on the surface where friction, shear and moisture are present and the heel meets the bed. It does not remove load, because the heel still carries the weight of the leg. Whether damp skin grips or slides depends on what it is touching, which is why the materials matter.

What the trials show at the heel

Starting with the broadest view, the 2024 Cochrane review of dressings for preventing pressure ulcers pooled 18 trials of silicone foam against no dressing, at all body sites, and found fewer ulcers with the dressing (risk ratio 0.50). The authors graded that evidence low or very low certainty and concluded that it is unclear whether any of the dressings studied make a difference to pressure ulcer development.

At the heel specifically, the 2025 International Pressure Injury Guideline pools four randomised trials. Heel injuries occurred in 1.5 per cent of people with a dressing and 3.7 per cent without (risk ratio 0.44, 95% confidence interval 0.21 to 0.95), graded low certainty.

Now the other figure, because it matters. The largest of those four trials, by Beeckman and colleagues in 2021, randomised 1,633 at-risk adults across eight Belgian hospitals in a pragmatic, noncommercial design. It found fewer pressure ulcers overall, and fewer at the sacrum. At the heel it found no difference: 1.4 per cent against 1.9 per cent, with a confidence interval running from a halving of risk to a near doubling (0.34 to 1.68).

The smaller trials pull the other way. The Border trial in Melbourne, which applied dressings to 440 trauma and critically ill patients from the emergency department through their intensive care stay, recorded 5 heel ulcers with the dressing against 19 without. Two of the four pooled trials were in intensive care, where baseline risk is high; one was in nursing homes; and the largest was on hospital wards. Three of the four tested the same manufacturer's dressings, Mölnlycke's Mepilex range.

So the pooled estimate favours dressings at the heel, at low certainty, and the largest trial found no heel effect. Both represent the evidence such as it is. Quoting the first without the second overstates the case.

KEY POINT: Across four heel trials, fewer heel injuries occurred with a dressing, at low certainty. The largest, a noncommercial trial on hospital wards, found no difference at the heel. Both figures belong in any conversation about a heel dressing protocol.

What the computer models show, and who paid for them

With so few trials, much of the argument for heel dressings rests on engineering. For example, finite element models that simulate the heel and calculate the strain inside it. As an engineer I take these models seriously. They show, consistently, that a well-designed dressing reduces internal strain and stress in a heel that is resting on a mattress and being moved sideways.

Two details matter however. The first is what the models compare. The two most recent, which I have read in full, rest the heel on a foam mattress, press the heel bone 4 mm into the tissue, then add 3.5 mm of sideways movement. The comparison is a dressed heel against a bare heel, both bearing load. No model I have found compares a dressing with a heel lifted clear of the mattress, which is the choice a tissue viability nurse actually faces.

The second is who paid. Here is what each paper declares, quoted wherever the paper itself is available to read:

Orlova and Gefen, 2026, modelling ConvaFoam Border: "This study was funded by Convatec Ltd., United Kingdom." and "Author A.G. is a paid consultant of Convatec Ltd."
Orlova, Orlov and Gefen, 2025, modelling Allevyn Complete Care: "Smith & Nephew Limited provided financial funding for this study. Author Amit Gefen is a paid consultant of Smith & Nephew Limited."
Marché, Creehan and Gefen, 2024, on Allevyn Life, supported by European and Israeli public grants: "In addition, Smith & Nephew Limited provided financial funding for this study."
Levy, Frank and Gefen, 2015, on a Mepilex Border Heel type dressing: the paper's funding record lists Mölnlycke Health Care.

I should declare my own interest in the same breath. Anatomical Concepts supplies the PRAFO, a heel suspension orthosis that floats the heel, and I am the company's founding director. Read what I say about offloading with that in mind.

The 2026 paper is careful about its own limits. Its protective effect depends on the dressing's skin layer becoming slippery as it takes up sweat. The authors note that people with diabetes, spinal cord injury or other nerve damage may not sweat, or may sweat less, so the friction may not fall to the level they modelled. Those are many of the patients whose heels worry us most. The authors also state plainly that the model gives mechanistic predictions, not direct evidence of clinical effectiveness.

KEY POINT: Computer models show dressings reducing strain in a heel that is resting on the mattress. They compare a dressed heel with a bare one, not with a floated one, and each paper's declared funding is set out above. They are evidence of mechanism, not of clinical effect.

Where the guideline and the NHS put dressings

The 2025 international guideline has four heel recommendations that belong side by side:

H1, a good practice statement: elevate the heels of people at risk so that they are not in contact with the support surface. This is the floating heel.
H2: use a heel offloading device appropriate to the person's mobility and activity level. Conditional recommendation; low certainty of evidence in the guideline's PDF, very low on its web page.
H4: a preventive dressing could be used "as an adjunct to heel elevation and regular repositioning", where resources permit. Conditional recommendation; low certainty of evidence.
H5: if a dressing is used, select a multilayered soft silicone foam dressing. Conditional recommendation; very low certainty of evidence.

Look at the grades. The dressing recommendation is at least as well supported as the offloading device recommendation: the guideline's PDF grades both low certainty, and its web page grades the device recommendation lower still, at very low. The device evidence is weak because it rests on two intensive care trials comparing an offloading boot with pillows. The guideline still puts floating first because H1 is a good practice statement. There is a clear consensus that the heel should not be touching the bed at all. This is a reflection of the mechanical realities of the situation.

What I cannot tell you is that a floated heel outperforms a dressed heel in a trial, because no trial has compared them. What I can tell you is the mechanism: a dressing reduces the shear on a heel that still bears the leg's weight, and floating takes the weight away completely.

The UK picture is quieter still. NICE's 2014 pressure ulcer guideline makes no recommendation on dressings for preventing pressure ulcers in adults; for heels it asks clinicians to discuss "a strategy to offload heel pressure". NICE's assessment of Mepilex Border Heel, now HealthTech guidance HTG495, found its clinical effectiveness uncertain, with only two observational studies of the heel dressing. The National Wound Care Strategy Programme's 2023 pressure ulcer pathway does not mention prophylactic dressings, and the programme completed its NHS England work in 2025. A large NHS trial in hip fracture patients, WHiTE14: PRESSURE 3, is testing heel offloading devices directly; its results have not yet been published.

KEY POINT: Floating the heel is the guideline's starting point, and the dressing is recommended alongside it, not instead of it. On certainty, the dressing recommendation is at least as well supported as the offloading device recommendation, and this is because the device trials are few. Neither NICE nor the national pressure ulcer pathway recommends prophylactic dressings for adults.

Using a dressing and a floating heel together

If your protocol uses heel dressings, the trials themselves show how they were meant to be used, and it was never on their own. In all four heel trials the heels were assessed daily and the dressings changed every three days, or sooner if they became soiled, dislodged or stopped adhering. The guideline's practical advice follows from that:

Lift the dressing and look at the heel every day. In the guideline's words, a preventive dressing "does not negate the need to evaluate the heel".
Mark prevention dressings so they are not mistaken for treatment dressings; the guideline suggests a letter P on the outside.
Encourage patients who walk to wear well-fitting shoes or gripped socks, because a dressed heel can slip.
Keep floating the heel. The dressing is the adjunct.

The problems nurses describe on that forum thread are nearly all failures of these steps: dressings left on for days, skin nobody has looked at, moisture under a dressing that was meant to help.

Some heels raise a different question altogether: high tone pushing the foot down, a patient who is agitated, a foot that is swollen or contracted. For those, the difficulty is keeping the heel off the bed at all, and a dressing does not change that. I have written about those heels in Heel Protection and the High-Tone Limb and about when to step up from a standard device in When a Soft Heel Boot Is Not Enough.

Conclusion

If you are a tissue viability nurse looking at your own protocol, three things are worth doing with your team. First, check what the protocol says the dressing is for. If it reads as the heel plan rather than an addition to floating the heel, the guideline would put it the other way round. Second, ask how often prevention dressings are actually lifted and the heel inspected; in the trials it was every day. Third, look at the patients whose heels still broke down with a dressing in place, and ask whether those heels were ever off the bed.

Where Anatomical Concepts comes in is the heel that needs floating and will not stay floated with pillows or a standard boot. The PRAFO range suspends the heel completely while carrying the leg and supporting the load along the calf. Fitting it is a matter of training and competence rather than profession, so tissue viability nurses, podiatrists, physiotherapists and district nurses can be trained to fit it, as orthotists do. We are glad to help with assessment, fitting and training, and to talk through which of your patients might benefit.

Decisions about any individual patient belong with the clinical team and the clinicians who assess them; nothing here replaces that.

And if you would simply like to compare notes on dressings, offloading or your own pathway, I'm always pleased to have that conversation. You can reach us through the contact page.

What a Prophylactic Dressing Can and Cannot Do for a Heel

What a dressing on a heel is actually doing

What the trials show at the heel

What the computer models show, and who paid for them

Where the guideline and the NHS put dressings

Using a dressing and a floating heel together

Conclusion

Further reading

Related articles on our site

Anatomical Concepts.
Every Body Better.

What a Prophylactic Dressing Can and Cannot Do for a Heel

What a dressing on a heel is actually doing

What the trials show at the heel

What the computer models show, and who paid for them

Where the guideline and the NHS put dressings

Using a dressing and a floating heel together

Conclusion

Further reading

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Anatomical Concepts.Every Body Better.

Anatomical Concepts.
Every Body Better.