Offloading is the practice of reducing or redistributing pressure on a wound so it can heal. It’s most commonly associated with diabetic foot ulcers, where excess pressure on the sole of the foot is a direct cause of ulcer formation and a major barrier to healing. But the concept applies broadly: any time sustained pressure on a wound is removed or spread across a larger area, that’s offloading. It can involve specialized casts, footwear, foam padding, mattresses, or even just repositioning a patient in bed on a regular schedule.
Why Pressure Prevents Healing
When you stand, walk, or lie in one position for too long, the weight of your body compresses tissue against bone. That compression restricts blood flow to the skin and underlying tissue. Without adequate blood supply, cells can’t get the oxygen and nutrients they need to repair damage. If a wound already exists, continued pressure essentially reinjures the area with every step or every hour spent in the same position.
Two forces are at work. Vertical pressure pushes straight down into the tissue. Shear force occurs when skin slides or pulls against a surface, like a foot shifting slightly inside a shoe. Both damage fragile healing tissue. Effective offloading addresses both by immobilizing the area, cushioning it, or redirecting force to healthier parts of the body.
Offloading for Diabetic Foot Ulcers
Diabetic foot ulcers are where offloading matters most. People with diabetes often develop nerve damage (neuropathy) that makes them unable to feel pain in their feet. They can’t sense the excessive pressure building under a bony area like the ball of the foot, so ulcers develop and worsen without the natural warning signals that would make most people shift their weight. Elevated plantar pressure is a direct causative factor in these ulcers, and those ulcers are a precursor to lower extremity amputation.
With proper offloading, real-world data shows about 33% of plantar diabetic foot ulcers heal within 12 weeks, roughly half heal by 20 weeks, and 77% heal within a year. Those numbers vary depending on the device used, the severity of the ulcer, and whether complications like infection or poor circulation are present. Without offloading, healing stalls or doesn’t happen at all, because every step reloads pressure onto the open wound.
The Gold Standard: Non-Removable Casts
The total contact cast is recognized as the gold standard for treating plantar diabetic foot ulcers. Every major national and international guideline endorses it. The cast works by encasing the entire lower leg and foot, spreading pressure across the whole sole rather than concentrating it on the ulcer site. The cast shank alone removes 30% to 36% of pressure from the foot compared to a standard cast shoe. It also locks the foot in place, controlling the shear forces that would otherwise pull at healing tissue.
Healing rates with total contact casts range from 89% to 92%, often over a shorter period than other devices. Part of the reason is simple: patients can’t take the cast off. This forced compliance means the ulcer stays protected around the clock. Studies show patients in total contact casts also walk less, take shorter strides, and move more slowly, all of which reduce repetitive stress on the wound. Patients frequently report that ulcers they’d had for years finally healed once they switched to a total contact cast.
The tradeoff is convenience. You can’t remove the cast to shower or sleep, which patients consistently cite as a drawback. The cast requires regular clinic visits for replacement, and it needs to be applied by a trained clinician. The 2023 guidelines from the International Working Group on the Diabetic Foot recommend a non-removable knee-high device as the first choice for neuropathic plantar forefoot or midfoot ulcers.
Removable Walkers and Other Devices
When a non-removable cast isn’t tolerated or is medically inappropriate, a removable knee-high or ankle-high walker is the second-line option. These look similar to the boots used after ankle fractures. They offer decent pressure redistribution and give patients the ability to remove the device for bathing and sleeping, which most people appreciate.
The problem is adherence. Because patients can take the walker off, many do so more often than they should. Studies show patients report frustration with slower healing in removable walkers, and several noted that the device didn’t fully immobilize their foot, allowing small movements that irritated the ulcer. At one year, healing rates with removable walkers reached about 73%, compared to 84% to 88% for orthopaedic shoes and total contact casts. That gap is largely attributed to the compliance difference.
If neither type of cast or walker is available, guidelines recommend felted foam combined with appropriate footwear as a third option. Felted foam is made from semi-compressed wool felt in sheets of 5 to 10 mm thickness. It has an adhesive backing and can be cut into custom shapes, with a hole or U-shape carved out around the wound site. This channels pressure away from the ulcer. It can be stuck directly to the foot, an insole, or the inside of a shoe. The limitation is that felt compresses over time, so it loses effectiveness after about a week of wear and needs to be replaced.
Therapeutic Footwear for Prevention
Once a diabetic foot ulcer has healed, the goal shifts to preventing recurrence, and that’s where therapeutic footwear comes in. These shoes are built with features that standard shoes lack: extra-deep toe boxes to accommodate deformities like claw toes, wide heels, seamless interiors that eliminate friction points, and enough depth to fit a custom insole.
The outsole design matters significantly. Rocker bottom soles curve upward at the toe, rolling the foot forward during walking so the ball of the foot bears less pressure at push-off. Studies show rigid rocker soles reduce plantar pressure more effectively than semi-rigid versions, and both outperform standard footwear in preventing ulcer recurrence on the metatarsal heads. Custom insoles inside these shoes further redistribute pressure based on each person’s foot shape and problem areas.
Offloading for Pressure Injuries
Offloading isn’t limited to feet. For patients who are bedridden or use wheelchairs, pressure injuries (also called bedsores or pressure ulcers) develop on the sacrum, heels, hips, and other bony areas that bear weight against a surface. Here, offloading means repositioning the patient regularly and using specialized support surfaces.
Guidelines from the UK’s National Institute for Health and Care Excellence recommend that people at risk of pressure ulcers change position at least every six hours. Those at high risk should reposition at least every four hours. When patients can’t move themselves, caregivers assist using equipment like hoists or slide sheets. Pressure-reducing mattresses play a major role: evidence shows that a pressure-reducing mattress combined with repositioning every four hours is more effective at preventing pressure ulcers than standard care alone. The mattress spreads body weight across a larger surface area, reducing the peak pressure on any single point.
Balance Problems and Fall Risk
One underappreciated risk of offloading devices is their effect on stability. People with diabetic neuropathy already have impaired balance and elevated fall risk. Adding an offloading device can make this worse. Rocker bottom shoes shift the center of pressure in ways that reduce postural stability. Thicker midsoles and smaller bases of support decrease balance control. Even insoles designed to reduce shear stress, which work by allowing slight lateral movement inside the shoe, can make patients with neuropathy feel unsteady.
Research has identified postural instability as the single strongest predictor of poor offloading adherence. If a device makes someone feel like they’re going to fall, they stop wearing it. This creates a difficult tradeoff: the devices that offload pressure most effectively tend to restrict movement and alter balance the most. Clinicians selecting an offloading device should consider a patient’s baseline steadiness, since someone with significant balance problems may do better with a lower-profile device they’ll actually wear than a more aggressive one they’ll leave in the closet.
When Surgery Becomes Necessary
If non-surgical offloading fails to heal a plantar forefoot ulcer, surgical options exist. The 2023 international guidelines recommend considering procedures like lengthening the Achilles tendon, removing a metatarsal head, joint replacement, or bone-cutting procedures in the forefoot. These operations permanently alter the foot’s structure to reduce pressure on the problem area. For ulcers on the tips of lesser toes caused by flexible toe deformities, a relatively minor procedure to release the tendon on the underside of the toe can resolve the pressure point. Surgery is a last resort, reserved for ulcers that persist despite months of appropriate non-surgical offloading.