Description
Calculate a supplied nonzero planar force resultant and direction.
Movement measurements depend on coordinate frames, force axes and torque references. Lateral separation can retain a signed direction as well as an absolute width, while a planar force angle requires a nonzero resultant. A supplied gravity correction is a recorded term rather than an estimate of anatomy or instrument behavior.
Calculate a supplied nonzero planar force resultant and direction.
When to use this tool
Use Force Plate Shear Resultant Angle when you already have forceX, forceY and need to calculate a supplied nonzero planar force resultant and direction.
How to use the tool and how it works
- Enter forceX, forceY. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read shearMagnitude, angleRadians. Use the output convention below.
Require at least one of forceX/forceY nonzero; return hypot(forceX,forceY) and atan2(forceY,forceX).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| forceX | Force X | Required. Finite number. |
| forceY | Force Y | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| shearMagnitude | Shear Magnitude | Required. Finite number. |
| angleRadians | atan2(forceY,forceX), measured from +x in the supplied plane; a nonzero vector is required. | Required. Finite number. |
{
"input": {
"forceX": 3,
"forceY": 4
},
"output": {
"shearMagnitude": 5,
"angleRadians": 0.9272952180016122
}
}Limitations and assumptions
- Angle is radians measured from the positive x axis under the supplied frame. No force trace, calibration, normal force or clinical interpretation is inferred.
- 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. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated motion and force records with the complete biomechanical model. Check axes, units and reference conventions before interpreting local geometry or torque differences as a movement or clinical finding.
References
Similar or alternative tools
- Gait Step Width From Foot Points
Measure supplied lateral foot-point separation.
- Dynamometer Gravity Correction Input
Subtract a supplied gravity-torque correction from recorded torque.