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What Is an Air Cast Boot?

Dan Cavallari
Dan Cavallari

When a person breaks a foot, ankle, or lower leg, they have the option to get the injured extremity sealed in a hard cast, or with their doctor's approval, they can opt for an air cast boot. An air cast boot encases the injured joint or foot inside an air cushion, which is in turn encased in a hard plastic shell. As an alternative to a traditional cast, the air cast boot promotes faster healing time, more mobility, and the ability to remove the cast so the injury can be exposed to fresh air or for convenience when showering. The boot is also more commonly used as a transition between a hard cast and no cast at all.

A patient must first and foremost check with their doctor to see if the air cast boot is the right choice for them. The boot should only be used as an alternative to a hard cast for minor injuries; otherwise, it can be used after a hard cast is taken off and before the ankle or foot is strong enough to bear weight on its own. The air cast boot allows a patient to slowly and safely promote strength in the foot or ankle, thereby allowing them to put weight on the injury more quickly after the injury occurs. It does so by keeping the foot and ankle at a constant angle but allowing a limited amount of movement within the cast, promoting mobility.

Air cast boot may be used with crutches.
Air cast boot may be used with crutches.

The air cells within the air cast boot are adjustable and can be made stiffer or softer by using a bulb pump. The hard shell of the boot keeps the ankle or foot in place, thereby reducing the possibility of re-injury caused by excessive movement. The hard shell also protects against external impacts. The sole of the boot is typically coated with non-skid material for safety and stability. By adjusting the boot using the Velcro® straps and the adjustable air cells, a patient can also reduce the risk of suffering from edema.

An air cast boot is custom fit.
An air cast boot is custom fit.

Depending on the severity of the injury, some patients may be able to use the air cast boot without crutches, thereby freeing their hands from the constraints of the crutches. Before attempting to walk without crutches, however, a patient should consult a doctor to prevent re-injuring the foot or ankle. The air cast boot is custom-fit to a patient, which increases comfort and the likelihood that the injury will heal correctly.

Pros and Cons of an Air Cast

Using an air cast has pros and cons to consider, which relate to the patient’s comfort and the effectiveness of the healing. 


If you require an air cast, you might be curious about how they can benefit you. Below are the pros of using an air cast. 

Patients Can Shower and Swim

An x-ray can be used to examine broken bones.
An x-ray can be used to examine broken bones.

One of the most significant advantages of air casts is they are not permanently applied to the limb, so patients can remove the cast to shower, swim, or allow the limb to breathe a bit. This option is typically more appealing to people that hate the idea of being trapped in a plaster or fiberglass cast for months.

Several Uses

Plaster is mostly just used for healing broken bones. But air casts are effective for breaks, strains, and post-surgical protection. 

Customizable Inflation

Unlike the traditional foot cast, an air cast boot can be removed.
Unlike the traditional foot cast, an air cast boot can be removed.

If a doctor applies a plaster cast or fiberglass too tightly or loosely, this is very hard to remedy without removing the entire cast and starting over. But an air cast has customizable inflation inside, so you can reduce the pressure or increase it to enhance your comfort. 


Fiberglass and plaster casts can be heavy and awkwardly rounding on the soul of the fit. Because of this design, they can make walking difficult and more tiresome for the patient. But air casts are much lighter, allowing the patient more mobility. 


In some cases, patients must be casted for several weeks before an air boot is used.
In some cases, patients must be casted for several weeks before an air boot is used.

Plaster and fiberglass can be affordable, but they can also cost hundreds or thousands of dollars because you need doctor assistance to apply and remove them. However, most air casts can be purchased for under $100, making them much easier to acquire. 


Below are the cons of wearing an air cast:

Interruptions to the Healing Process

The only major con of an air cast is that the patient can easily remove it often, which can delay and disrupt the healing process. If removed often, the bone may not heal correctly, causing lifelong problems. 

The Evolution of Casts

The air cast boot is one of the best ways to heal broken or fractured limbs and is far more comfortable than older kinds of casts. To understand the brilliance of the air cast, let’s discuss the evolution of casts and the immobilization of injured limbs. 


The beginning of immobilization of injured limbs started in ancient Egypt. They used wood splints and treebark to fix injured limbs to help them heal.


Ancient Hindus used bamboo splits to immobilize and treat broken bones. 


The ancient Greeks used wax and resin to stiffen bandages, much like the plaster casts people are familiar with today. 


Ancient Arabs also took the route of stiffening soft bandages to immobilize the limb. However, they used the lime properties obtained from seashells and egg whites to strengthen the bandaging. 


Italians, true to their culture that loves food, used a combination of eggs and flour on pliable casts to stiffen them and hold the limb in one place until it healed. 


Germans would place narrow boxes around injured limbs and then fill them with wet sand, making it impossible to move the limb. While effective in healing, this method forced the patient to stay in bed and drastically immobilized them.


A major milestone in the development of casts was The Plaster of Paris. This plaster was a mixture of powdered gypsum and water, forming a plaster that hardens after drying. The plaster was developed in the 1850s by Nikolay Ivanovich Pirogov and Anthonius Mathijsen, two military doctors and surgeons active during the Crimean War. 

The Plaster of Paris was the chosen type of cast for over a century. It was advantageous compared with splints but was very heavy and was generally uncomfortable for patients. 

Modern Casts

The next evolution of the cast was the fiberglass cast. These casts came about in the 1970s and quickly became the preferred replacement over The Plaster of Paris. Fiberglass casts are much lighter and waterproof, making them more comfortable for injured patients. 

And finally, the inventor Glenn Walter Johnson Jr. created an ankle brace designed for sprains that eventually became the air cast boot in the mid-1970s. 

The air cast is much lighter and more durable than fiberglass or plaster casts, prioritizing comfort without sacrificing the integrity of the healing process. 

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Discussion Comments


I have an air boot for a broken heel bone. It is somewhat heavy and I have crutches but do not use them much. Since I am not using the crutches, I tend to walk on my toes on that foot so I do not make the bone any worse. I was sleeping in it but it was so uncomfortable I took it off and slept much better. I just put it back on as soon as I am out of bed. I also take it off when I shower.


I had a Brostrom procedure and opted for the aircast instead of a cast, mainly due to some cast claustrophobia. The doctor said it gives me the same support as the fiberglass cast as long as I wear it and I am determined to follow his advice, but for comfort I need as much of my foot exposed as possible.

I live in Arizona and it's already over 100 degrees here. All I want to do is uncover my toes. I don't see that covering my toes up has any support benefit for an ankle injury and I've been allowed to wiggle my toes for two weeks now in my splint. The plastic plate at the top of my foot and the velcro is still going to keep my foot fairly motionless.

Can I cut off the flap at the end and the very toe part of the stockinette without compromising any support or without exposing myself to any chafing?


I can't see that just a boot would be much use for a sprain. Far more useful would be compressive support bandages - at least in my experience (I've had a few sprained ankles).

The air cast would not take well to being soaked in a shower as it's lined with foam that will thus get soggy. If you want a shower the recommendation is to use a shower chair so you can free the leg and wash it without putting weight on it.

And the ability to take it off is huge. To be able to sit down on the couch and put your leg up free of Das Boot is priceless. The stockings easily get caught on the velcro fastenings, so it's worth having a number on hand.

I was told I had to keep it in on in bed, so I did. I'd as soon have not, but I was interested in healing as fast as possible so I wasn't going to challenge Ortho-mans instructions.

I also found the flat base of the air cast to be annoyingly unsupportive - so I picked up some quality show inserts and tried putting one inside the stocking, which kept it on the foot in the aircast. This helped immensely in supporting the foot/instep and heel - though, of course, your mileage may vary and I'd recommend talking to your doctor first depending on what your injury was. In my case, a totally ruptured Achilles repaired by an FHL transfer.


I dislocated my ankle and fracture my fibula, slipping on ice. I had two screws put in. Wearing the air cast sleeve (it's a long, loose cotton stocking) is a must to reduce discomfort. If you did not get this at the clinic, you can order them online.

I reduce the inflation a bit at night for comfort. If there is pain from pressure on the injury point, shin, or on the sutures, you can use large band aids. I use the ones with antibiotics as this adds moisture and also helps reduce scarring. Odor Eaters powder helps cool off the foot and prevents odors. --GLTA


My son broke his ankle and is in an air cast and we were told not to wear it in the shower. @naturegurl3: He can only take it off for baths or showers and that is it.


Can I use an aircast and go totally without crutches three weeks after my bone graft surgery?


I need an air cast boot for my foot. I had a minor fracture on my foot. How much is the air cast boot going to cost me? --Funmi, Lagos, Nigeria


I have a question: can I wear boot cast to bed because I have hard sleeps and do not want to bang anything to hurt my foot. And even if you are staying at home, do you have to wear it? I thought it was a walking boot for outdoors.


I sprained my foot and was given a boot. After two hours of wearing it, my heel was killing me. I have plantar fasciitis on both heels. Now what?


Do you wear it 24/7 other than showering or cleaning the boot, e.g., do you take it off at night?


You can wear it in the shower covered like any other cast, if you can't put any weight on the foot and might slip in the shower. You can't wear it uncovered as there is a lot of padding, etc., that would not be good if wet!


I needed someone's advice. with cast boots, must you use crutches? Will be grateful if someone could say.


@naturesgurl3 -- I think that while you could wear it in the shower, the whole point of wearing an air cast is that you can take it off, so that you can shower without it.

So although you probably could wear one in the shower, you really shouldn't, and there's really no reason not to take it off -- I mean, that's what they are designed to do.


Can you wear an air cast in the shower? Since it's plastic I thought that would be OK, but my brother says you can't.

Does anybody know?


I was so glad that I had an air cast walking boot when I sprained my ankle -- it was so much more convenient than if I had to wear a hard cast.

However, I know it is important for the patient to know how to reapply the cast properly.

In fact, this is one of the biggest disadvantages of air casts. If the patient puts it back on incorrectly then it can keep the injury from healing properly, or even delay the healing process altogether.

So if you get an air cast, be sure to follow all the doctor's instructions -- it will really save you some headaches down the road.

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    • Air cast boot may be used with crutches.
      By: klickerminth
      Air cast boot may be used with crutches.
    • An air cast boot is custom fit.
      By: Julián Rovagnati
      An air cast boot is custom fit.
    • An x-ray can be used to examine broken bones.
      By: eAlisa
      An x-ray can be used to examine broken bones.
    • Unlike the traditional foot cast, an air cast boot can be removed.
      By: Olena Talberg
      Unlike the traditional foot cast, an air cast boot can be removed.
    • In some cases, patients must be casted for several weeks before an air boot is used.
      By: Fotoluminate LLC
      In some cases, patients must be casted for several weeks before an air boot is used.