Flat feet — also called fallen arches or overpronation — affect an estimated 20–30% of Australians. For many people, flat feet cause no problems. But for others, the collapse of the arch leads to a chain reaction of pain affecting the feet, ankles, knees, hips, and 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 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 pronation, redistributing load more evenly across the foot and lower limb.
Best insoles for flat feet
1. Trekker Orthotics
A great first choice for flat feet, especially for people who are active or on their feet all day. Firm medial arch support controls overpronation effectively and holds up well under sustained daily use. Popular with walkers and people in occupational footwear.
2. Formthotics
Heat-mouldable — customised to match your exact foot shape. Particularly good for flat feet as the orthotic conforms precisely to where your arch sits. The dual density construction provides both arch support and forefoot cushioning.
3. PowerStep
One of the most prescribed orthotic brands in the world. Features a semi-rigid shell for motion control, dual-layer cushioning, and a deep heel cradle — an excellent choice for moderate to severe overpronation.
Choosing the right density
One of the most common mistakes is choosing an insole that's too soft. For flat feet and overpronation, you need a firm or semi-rigid orthotic with enough structure to 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 flat shoes, thongs, and minimalist footwear.
Do you need custom orthotics?
Off-the-shelf orthotics work well for the majority of people with flat feet. Custom orthotics are recommended when off-the-shelf options haven't provided enough relief after 6–8 weeks, or when a specific structural deformity requires precise correction.
Browse our full orthotics and insoles range or our heel and arch pain collection for podiatrist-recommended products that work for flat feet and overpronation.