Össur Formfit Cast Boot (Short / Low-Top, Open-Toe) – Pneumatic CAM Walking Boot
Looking for a cast boot, CAM boot, walking boot, fracture boot, or orthopedic boot that’s affordable and lightweight? The Össur Formfit Walker Air Short (Low-Top) is a rugged, open-toe medical boot designed to immobilize the foot/ankle at 90° while allowing controlled walking (as prescribed).
What this is (and what patients call it)
This is a removable CAM walker boot (Controlled Ankle Movement). Many people call the same device a cast boot or walking cast boot, even though it’s removable. It’s also commonly searched as an aircast boot or “boot for broken foot.”
Important Fit Tip: boots fit a size range (not a perfect shoe fit)
A very common issue with any medical boot is that sizing is based on a shoe-size range to leave room for swelling, thicker socks, and dressings. If you’re at the low end of the range, the boot can feel roomier. If you’re at the top end, it will feel closer to “perfect.”
- Seat your heel fully back before tightening straps.
- Tighten straps evenly (don’t over-tighten one strap and leave others loose).
- Use the air bladders to take up extra volume (avoid over-inflation).
- If between sizes: minimal swelling / narrow foot → smaller may feel more secure; swelling/dressings → stay in range or size up.
Size Chart
Internal Measurements + Height + Weight (Low-Top)
These measurements help dial in fit beyond just shoe size—especially helpful when customers say their cast boot feels big or small.
| Size | Men’s shoe range | Women’s shoe range | Internal foot length | Height (heel → top) | Boot weight |
|---|---|---|---|---|---|
| XS | 2 – 4.5 | 3.5 – 6 | 22.0 cm (8.66") | 29.5 cm (11.6") | 825 g (1.82 lb) |
| S | 4.5 – 7.5 | 6 – 8 | 24.0 cm (9.45") | 29.5 cm (11.6") | 890 g (1.96 lb) |
| M | 7.5 – 10.5 | 8.5 – 11.5 | 27.0 cm (10.63") | 32.0 cm (12.6") | 1030 g (2.27 lb) |
| L | 10.5 – 12.5 | 11.5 – 13.5 | 28.0 cm (11.02") | 34.0 cm (13.4") | 1180 g (2.60 lb) |
| XL | 12.5+ | 13.5+ | 30.2 cm (11.89") | 34.0 cm (13.4") | 1220 g (2.69 lb) |
Tip: For best results, compare your measured foot length (heel to longest toe) to the “internal foot length” and leave a little room for swelling.
Why patients choose this cast boot
The Formfit Walker Air Short is a lightweight, affordable alternative to conventional casting. The biggest advantage over a cast is the ability to remove the boot for hygiene (only if allowed by the clinician), adjust fit as swelling changes, and walk with a more natural gait pattern using the rocker bottom.
The integrated pneumatic system can help increase stability and accommodate changing swelling patterns throughout rehab. The shock-absorbing sole reduces impact at heel strike for improved comfort during ambulation.
Fitting Video
This video shows the low-top non-inflated version. Fit and application are very similar; this model adds inflatable air bladders.
Low-Top vs High-Top (quick guidance)
The low-top range is commonly used for foot problems where the ankle is less affected. If you need more ankle control or higher coverage, consider the high-top version (as prescribed).
Indications (as prescribed)
- Soft tissue injuries
- Grade 2 and 3 sprains
- Stable fractures
- Post-operative, trauma, or rehab use
Features & Benefits
- Open-toe design for breathability and easier toe checks
- Integrated pneumatic system for adjustable compression
- Low, wide rocker bottom promotes a stable, natural gait
- Shock-absorbing sole reduces impact at heel strike
- Breathable, seamless liner
- Designed for outdoor use where traditional casts can be limiting
Reimbursement Code: L4361
Shipping: Based on your location, ships from NJ or CA warehouse in 2–3 business days.
Authorized Dealer: Authentic product • 6-month manufacturer warranty • Support: 800-580-9887 (M–F 9:30–5:00 EST)
Also Available: Formfit High-Top
Need more ankle coverage? The high-top version offers taller support (as prescribed).
Authorized Dealer | 6-Month Manufacturer Warranty | Authentic Product Quality Guaranteed
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Call: 800-580-9887 (M–F 9:30–5:00 EST)