Description
Compare supplied research foot lengths with independent bounded measurement errors.
Foot and footwear research uses geometric dimensions, contact cells, forces, and measurement records. A length margin, normalized difference, or contact share has a specific measurement basis and can omit important three-dimensional or sensor effects. Arithmetic on supplied observations is separate from a validated clinical assessment.
Compare supplied research foot lengths with independent bounded measurement errors.
When to use this tool
Use Podiatry Research Left Right Length Gap when you have supplied foot, footwear, bench, or recording data and need this measurement or record-support calculation.
How to use the tool and how it works
- Enter left, right, leftHalfwidth, rightHalfwidth. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedGap, lowerGap, upperGap, relativeGap. Use the output convention below.
For positive left and right lengths and nonnegative halfwidths return signedGap=left-right, lowerGap=signedGap-leftHalfwidth-rightHalfwidth, upperGap=signedGap+leftHalfwidth+rightHalfwidth, and relativeGap=2*signedGap/(left+right).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| left | Left | Required. Finite number; strictly above 0. |
| right | Right | Required. Finite number; strictly above 0. |
| leftHalfwidth | Left Halfwidth | Required. Finite number; minimum 0. |
| rightHalfwidth | Right Halfwidth | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedGap | Signed Gap | Required. Finite number. |
| lowerGap | Lower Gap | Required. Finite number. |
| upperGap | Upper Gap | Required. Finite number. |
| relativeGap | Relative Gap | Required. Finite number. |
{
"input": {
"left": 250,
"right": 248,
"leftHalfwidth": 1,
"rightHalfwidth": 1
},
"output": {
"signedGap": 2,
"lowerGap": 0,
"upperGap": 4,
"relativeGap": 0.008032128514056224
}
}Limitations and assumptions
- Lengths and halfwidths need one unit. The interval uses supplied absolute bounds, not an inferred confidence interval; asymmetry alone is not a diagnosis.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Signed zero is exported as zero.
Alternative or Complementary methods
Use a documented measurement protocol with calibrated equipment and appropriate geometric or contact models. Broader interpretation requires assessment of the underlying observations beyond one length, ratio, or support flag.
References
Similar or alternative tools
- Foot Length Width Size Chart Source Pair
Retain supplied chart/source and unit context without selecting a shoe size.
- Gait Research Step Width Normalizer
For positive legLength and scaleFactor return signedWidth=secondLateral-firstLateral, absoluteWidth=abs(signedWidth), and normalized=absoluteWidth*scaleFactor/legLength.