Offloading Devices
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, October 2026
Offloading devices are casts, boots and special shoes that take pressure off part of your foot, mostly a sore (ulcer) or an at-risk spot. They are best proven for adults with diabetes who have lost feeling in their feet and have a sore under the front or middle of the foot. A cast that you can't take off is the first choice, and these sores often heal in about 6 weeks. Wearing the device as directed matters most. After the sore heals, pressure-relieving footwear helps stop it coming back.
What is it?
Offloading devices are casts, boots, shoes and similar devices that take pressure off part of your foot. They are mostly used for a sore (ulcer) or a spot on your foot that is at risk. By taking pressure off, they help sores heal and help stop new ones forming or coming back.
In people with diabetes, extra pressure under the foot and the repeated stress of walking help break down skin and tissue. Offloading moves that stress away from high-pressure spots, such as bony bumps.
The best-known device is the total contact cast (TCC). It is a cast that runs from your toes to your knee and moves your weight onto your leg. An instant TCC is a walking boot that reaches to the knee and is made non-removable with a wrap. Other devices include boots that you can take off, ankle-high boots and therapeutic footwear (specially made shoes and insoles).
Offloading is one part of foot ulcer care. It works alongside wound care.
What is it used for?
The best-supported use is healing a sore under the front or middle of the foot in an adult with diabetes who has lost feeling in the foot (neuropathy). For these sores, a knee-high device that you can't take off is the first choice in the 2023 international guideline.
Offloading is also used to stop sores coming back. Therapeutic footwear that relieves pressure, and that you actually wear, reduces the chance of the same sore returning.
For other kinds of sores, it isn't yet clear how well offloading works. These include heel sores, sores that aren't on the sole of the foot, and sores that are infected or have a poor blood supply. It also isn't clear for preventing a first sore. Your care team will make these decisions case by case.
Health services also use total contact casts for foot fractures, wounds after surgery and a foot condition called Charcot neuroarthropathy. It isn't yet clear how well casts work for these.
Is it right for me?
A cast or device that you can't take off is the first choice if you are an adult with diabetes and a sore under the front or middle of your foot. It suits you if there is no reason against it, you can cope with wearing it, and your foot fits it safely.
A device you can't take off should not be used if you have:
- an infection in the soft tissue of the foot or leg
- an infection in the bone (osteomyelitis)
- severe problems with the blood supply to your legs and feet (severe vascular disease)
- severe swelling of the lower leg or foot
If you have milder blood supply problems, your blood supply should be checked first, and you will need close follow-up.
If a cast isn't suitable or you can't cope with one, the next choices are, in order, a removable knee-high boot, a removable ankle-high boot, and then therapeutic footwear as a last resort.
Most of the research is in adults with diabetes and nerve damage in the foot. If you are a child, don't have diabetes, or have a heel sore or a sore that is infected or has a poor blood supply, you should have a specialist assessment before offloading.
Before you choose a device, talk with your podiatrist about how it will affect your daily life. A cast reduces how much you can move, and you can't check the sore yourself each day.
What happens?
A total contact cast is made of tape that isn't fibreglass. It takes about 20 to 30 minutes to put on, usually from your toes to your knee. Your podiatry team usually sees you each week. They take the cast off, check your foot, and put on a new cast if you still need one. You may need a cast for many months.
While you wear a cast:
- Keep it dry. You can buy waterproof protectors.
- Never take it off yourself.
- Look at the skin that shows around the cast every day for irritation, swelling or colour changes.
- Check that the cast isn't too tight, loose, soft, cracked, wet or dirty.
If your device is removable, you need to wear it for at least 80 per cent of your daily activity for it to work. In practice, removable walking casts are worn on average for only about 59 per cent of daily activity, and therapeutic footwear for about 50.3 per cent. Aim to wear it whenever you are on your feet.
How well does it work?
For sores under the front or middle of the foot, casts and other devices you can't take off heal more sores than removable devices. They also heal more sores than dressings alone. Removable knee-high and ankle-high boots are the second choice, and they work about equally well as each other. Ordinary shoes are not effective for healing a sore.
Part of the cast advantage comes from the fact that you can't take it off. Even the best device won't work if it isn't worn. People with larger sores, or with nerve or blood supply pain, tend to wear their devices more than people with small, painless sores. Understanding that a sore you can't feel is still serious can help you keep wearing your device.
Sores under the foot that have nerve damage and no complications typically heal in about 6 weeks with a cast. Uncomplicated sores should heal in 6 to 8 weeks with good offloading. If your sore is healing more slowly, your care team will want to review your care.
If non-surgical offloading doesn't heal a sore at the front of the foot, your care team may consider surgery. Options include lengthening the Achilles tendon (the big tendon at the back of your ankle), removing part of a bone at the base of a toe, or reshaping a joint or bone. These usually add a small to moderate benefit, with more side effects and higher costs.
Risks and side effects
Casts you can't take off have more device problems than removable options overall. The main problems are the cast failing and skin problems. The difference is clearest against therapeutic footwear. Compared with removable walking casts, there is no clear difference.
A cast can rub and cause a new sore on another part of your foot or leg. If you have lost feeling in your foot, you may not notice it happening, so check your skin every day.
A cast reduces how much you can move, and you can't look at your sore each day. You may also find you can't work while you wear it.
Rarely, wearing a cast leads to a blood clot in a leg vein (deep vein thrombosis, or DVT). A clot can travel to the lungs (pulmonary embolism). The warning signs are listed below.
Surgery added to a device has its own risks. Lengthening the Achilles tendon is likely to cause more new heel sores. Cutting a tendon in a toe may cause new sores where the pressure moves to.
Afterwards
Once your sore has healed, the aim is to stop it coming back. Therapeutic footwear that relieves pressure, and that you really wear, reduces the chance of a new sore in the same place. Custom shoe inserts (orthotics) and shoes are also used to lower the pressure under your foot.
As with the cast, the benefit depends on wearing them. Talk with your podiatrist about the right footwear for you before you stop using your device.
When to see a podiatrist
Book an appointment if
Your sore is healing more slowly than expected, you find your device hard to wear as directed, or it is uncomfortable. Also book once your sore has healed, so your podiatrist can plan protective footwear to help stop it coming back.
Seek prompt assessment if
Call your local emergency number if you suddenly become short of breath, have chest pain or upper back pain that is worse when you breathe in deeply, or cough up blood, especially while wearing a cast. Also call if your leg, foot or toes suddenly turn cold and pale or blue, with pain or numbness, or if your toes turn blue or white in your cast. If you have a foot sore or infection and you also feel very unwell, with confusion or slurred speech, severe shivering or muscle pain, severe breathlessness, mottled or discoloured skin, or little or no urine, this could be sepsis: call your local emergency number. See your GP or another doctor today if you have pain or swelling in your calf or thigh while wearing a cast. Don't wait for your next clinic visit. If your GP can't see you today, go to an urgent care clinic or an after-hours GP. Contact the clinic that applied your cast straight away if you fall or trip, have new or worse pain, redness, a worsening sore or a flu-like illness. If you can't reach them, see your GP or another doctor today. Don't take the cast off yourself. Contact the clinic promptly if your cast feels too tight, loose, soft, cracked, wet or dirty, or if you get new tingling or numbness in your toes. If you have a foot sore that no podiatrist or high-risk foot service has seen, don't wait. See your podiatrist or a high-risk foot service without delay. Until then, cover the sore with a suitable dressing and keep it dry.
Frequently asked questions
Why can't I take my cast off to look at my foot?
The cast only works if it stays on, because it keeps your weight off the sore all the time. Taking it off lets pressure back on to the sore. Your podiatry team removes it each week, usually, to check your foot and put on a new cast if needed. Look at the skin around the cast yourself every day.
Can I fly or work while I wear a cast?
You can't travel by aeroplane while you have a cast on. You may also find you can't work, because the cast limits how much you can move. Talk with your podiatrist early about your job and any travel plans, so you can plan around them.
Can ordinary shoes do the same job?
No. Ordinary or standard footwear isn't effective for healing a sore. Therapeutic footwear is used only as a last resort when you can't manage or get any other device. After healing, pressure-relieving therapeutic footwear that you wear is what helps keep the sore from returning.