Muscle Force Quantification Tool
Fit a linear force-transducer calibration and apply it to recordings, preserving signed estimates outside calibration; no strength norms are embedded.
Description
Force calibration maps sensor readings to known loads.
Force calibration maps sensor readings to known loads. A fitted intercept accounts for an offset rather than assuming the sensor reads zero at zero force.
The tool returns newtonsPerReadingUnit (newtons per reading unit); forceInterceptNewtons (force intercept newtons); estimatedForcesNewtons (estimated forces newtons); calibrationRSquared (calibration r squared). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Muscle Force Quantification Tool
Use Muscle Force Quantification Tool when you already have knownForcesNewtons, calibrationReadings, measurementReadings and want newtonsPerReadingUnit, forceInterceptNewtons, estimatedForcesNewtons, calibrationRSquared. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Muscle Force Quantification Tool and understand its results
- Enter knownForcesNewtons, calibrationReadings, measurementReadings using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read newtonsPerReadingUnit, forceInterceptNewtons, estimatedForcesNewtons, calibrationRSquared. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| knownForcesNewtons | Known forces newtons | list of number | Required |
| calibrationReadings | Calibration readings | list of number | Required |
| measurementReadings | Measurement readings | list of number | Required |
Fit an intercept and positive slope from paired calibration readings and nonnegative known forces. Apply the same equation to a nonempty measurement list.
forceNewtons = intercept+slope×reading The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"knownForcesNewtons": [
0,
10,
20
],
"calibrationReadings": [
1,
3,
5
],
"measurementReadings": [
2,
4
]
},
"output": {
"newtonsPerReadingUnit": 5,
"forceInterceptNewtons": -5,
"estimatedForcesNewtons": [
5,
15
],
"calibrationRSquared": 1
}
}Limitations and assumptions
Extrapolated forces can be negative. Drift, nonlinear response and load-dependent error are not corrected.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Twitch Force: Measure sampled twitch peak and net impulse after baseline subtraction across explicit disjoint windows; force must already be calibrated. Twitch Interpolation Voluntary Activation: Calculate paired trial voluntary activation as 100·(1−superimposed/rest potentiated twitch); negative estimates are preserved to expose model/protocol incompatibility, not clipped.
Methodological background: Least squares estimation.1
References
-
Least squares estimation — NIST/SEMATECH
Similar or alternative tools
- Twitch Force
Measure sampled twitch peak and net impulse after baseline subtraction across explicit disjoint windows; force must already be calibrated.
- Twitch Interpolation Voluntary Activation
Calculate paired trial voluntary activation as 100·(1−superimposed/rest potentiated twitch); negative estimates are preserved to expose model/protocol incompatibility, not clipped.