Flat feet — also called fallen arches or overpronation — affect an estimated 20–30% of Australians. For many people, flat feet cause no problems at all. But for others, the collapse of the arch leads to a chain reaction of pain and discomfort that can affect the feet, ankles, knees, hips, and even the lower back.
The right insole can correct overpronation, reduce pain, and make a real difference to how you feel after a long day on your feet. Here's what actually works.
How flat feet cause pain
When the arch collapses, the foot rolls inward (pronates) with each step. This inward rolling motion creates abnormal stress on the plantar fascia, Achilles tendon, and tibialis posterior tendon — the structures most commonly involved in flat foot pain. Over time it also places extra load on the knees and hips.
An orthotic insole works by supporting the arch and controlling the amount of pronation, redistributing load more evenly across the foot and lower limb.
Best insoles for flat feet
1. Trekker Orthotics
Trekker orthotics are a great first choice for flat feet, especially for people who are active or on their feet all day. Designed with a firm base and strong medial arch support, they control overpronation effectively and hold up well under sustained daily use. A particularly popular option for walkers and people in occupational footwear.
2. Formthotics Dual Density
Formthotics are heat-mouldable — meaning they can be customised to match your exact foot shape using a heat gun or oven. This makes them a particularly good choice for people with flat feet, as the orthotic conforms precisely to where your arch sits (or used to sit). The dual density construction provides both arch support and forefoot cushioning.
3. ArchLine Orthotics
ArchLine is an Australian brand specifically designed for people with flat feet and overpronation. Their orthotics feature a high medial arch support and a firm base that holds up under daily use. Popular with people who work on their feet all day in occupational footwear.
4. FootBionics
FootBionics orthotics use a unique tri-planar motion control design to address overpronation from multiple angles. A good choice for more severe flat feet where standard arch support insoles haven't provided enough control.
Choosing the right density
One of the most common mistakes when buying orthotics for flat feet is choosing an insole that's too soft. For flat feet and overpronation, you generally need a firm or semi-rigid orthotic — something with enough structure to actually hold the arch up under your body weight.
- Under 70kg — Medium density is usually sufficient
- 70–90kg — Firm density recommended
- Over 90kg — Extra firm or dual density for adequate support
Footwear matters too
Even the best orthotic won't work well in a flat, unsupportive shoe. For flat feet, look for footwear with a firm heel counter, a slight heel raise, and enough depth to accommodate an orthotic insert. Avoid completely flat shoes, thongs, and minimalist footwear — these remove whatever arch support your foot naturally has.
Do you need custom orthotics?
Off-the-shelf orthotics work well for the majority of people with flat feet. Custom orthotics — made from a plaster cast or 3D scan of your foot — are recommended when off-the-shelf options haven't provided enough relief after 6–8 weeks, or when you have a specific structural deformity that requires a precise correction.
Browse our full orthotics range or our arch support collection to find the right insole for your flat feet.