Walk into a pharmacy or sports store and you'll find a wall of orthotic insoles, all claiming to fix heel pain, flat feet, and plantar fasciitis. The reality is that the right orthotic for you depends entirely on your foot type, body weight, activity level, and footwear — and choosing the wrong one can actually make symptoms worse. Here's how to cut through the noise.
First: what does an orthotic actually do?
An orthotic insole works by modifying the way load is distributed through the foot and lower limb with every step. Depending on the design, it can:
- Support the arch and reduce overpronation
- Cushion high-impact areas (heel, metatarsal heads)
- Control the alignment of the heel (rearfoot posting)
- Offload painful structures (e.g. plantar fascia, metatarsal heads)
- Compensate for structural asymmetries (e.g. leg length discrepancy)
No single orthotic does all of these things equally well. Understanding which you need is the starting point.
Step 1: Know your foot type
Flat feet (overpronation) — The arch collapses inward during walking. You need a firm or semi-rigid orthotic with strong medial arch support to control pronation. An orthotic that is too soft won't hold the arch up under body weight and will provide no biomechanical correction.
High-arched feet (supination) — The foot rolls outward and absorbs shock poorly. You need a cushioned orthotic rather than a motion-control device — the goal is to add the shock absorption your foot lacks naturally.
Neutral arch — For everyday comfort and plantar fasciitis prevention, a semi-rigid orthotic with moderate arch support and heel cushioning works well for most neutral-arched feet.
Step 2: Match density to body weight
This is where most people go wrong when buying orthotics. An orthotic that provides excellent support for a 60kg person will bottom out under a 90kg person — they need a fundamentally different product.
- Under 60kg — Medium density or dual density with soft top layer
- 60–80kg — Firm density
- 80–100kg — Extra firm density
- Over 100kg — Extra firm or a rigid shell orthotic designed for higher body weight
Step 3: Match the orthotic to the footwear
A full-length orthotic won't fit in a dress shoe or cycling shoe. A 3/4 length orthotic works in a wider range of footwear because it doesn't reach the toe box. Consider:
- Full length — Running shoes, walking shoes, work boots, casual lace-ups
- 3/4 length — Dress shoes, court shoes, some cycling shoes
- Slim profile — Flats, fashion footwear, work shoes with limited depth
Step 4: Consider heat moulding
Heat-mouldable orthotics like Formthotics can be customised to your exact foot shape at home or in a podiatry clinic. This gives you the biomechanical precision of a custom orthotic at a fraction of the cost, and is particularly valuable for people with unusual foot shapes or specific structural deformities.
Our most popular orthotic ranges
- Formthotics — heat-mouldable, New Zealand-made, podiatrist's first choice
- Trekker Orthotics — firm density, durable, excellent value for flat feet and occupational use
- PowerStep — globally prescribed, semi-rigid shell, dual density cushioning
Browse our complete orthotics and insoles range or contact us for a recommendation based on your specific symptoms and foot type.
Disclaimer: This guide is for general information only. For complex foot conditions, a full podiatric biomechanical assessment and custom orthotic prescription may be appropriate.