Foot length measurement methods
| Measurement tools | |
| Firm ruler (plastic, metal, wooden) (See online supplemental WebAppendix 7a) | Firm; low cost and locally accessible; does not required specialised tool or procurement. |
| Sliding callipers | Precise however requires specialised tool, more costly and difficult to procurethan ruler. |
| Flexible measuring tape | Low cost, locally available. Flexible tape is not fixed or firm; may be less reliable and prone to variation between measurements. |
| Footprint (See online supplemental WebAppendix 4a: eFigure 1) | Requires firm surface. Can be measured retrospectively. Challenges include local/cultural beliefs regarding foot/finger prints and requires cleaning foot afterwards. |
| Foot length measuring board (See online supplemental WebAppendix 7b) | Precise, reliable; however, requires specialised tool that maybe difficult to manufacture or procure. |
| Measurement Techniques/Axis | |
| Heel-to-hallux | Linear distance measured from the base of the heel to the tip of hallux (big toe) |
| Heel-to-longest toe | Linear distance measured from the base of the heel to the tip of the longest toe (first, second, or third digit) |
| Vertical distance | Linear distance measured from the base of the heel to longest digit, along vertical axis of foot |