Description
Return spin and supplied planar orbital momentum terms.
Mechanical inertia, torque and muscle-force projections require compatible axes, origins and geometric assumptions. A parallel-axis contribution, planar moment or ideal pennation factor is one local model term rather than a full anatomical load or muscle-activation calculation.
Return spin and supplied planar orbital momentum terms.
When to use this tool
Use Segment Angular Momentum Inertia Term when evaluating the stated segment, moment, inertia or ideal muscle-geometry term.
How to use the tool and how it works
- Enter inertia, angularSpeed, centerMass, centerPosition, centerVelocity. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read spinMomentum, planarOrbitalMomentum, total. Use the output convention below.
Return spin and supplied planar orbital momentum terms. Require inertia and centerMass >= 0; spin = inertia*angularSpeed, orbital = mass*centerPosition*centerVelocity, total sums them.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| inertia | Inertia | Required. Finite number; minimum 0. |
| angularSpeed | Angular Speed | Required. Finite number. |
| centerMass | Center Mass | Required. Finite number; minimum 0. |
| centerPosition | Supplied signed lever component for the scalar planar orbital convention. | Required. Finite number. |
| centerVelocity | Supplied matching perpendicular signed velocity component; no vector cross product is computed. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| spinMomentum | Spin Momentum | Required. Finite number. |
| planarOrbitalMomentum | Planar Orbital Momentum | Required. Finite number. |
| total | Total | Required. Finite number. |
{
"input": {
"inertia": 2,
"angularSpeed": 3,
"centerMass": 4,
"centerPosition": 2,
"centerVelocity": 1
},
"output": {
"spinMomentum": 6,
"planarOrbitalMomentum": 8,
"total": 14
}
}Limitations and assumptions
- Position and velocity are caller-supplied signed perpendicular components for this scalar convention; no vector cross product or anatomical frame 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 verified anatomy and calibration, a consistent coordinate frame and a complete appropriate mechanical model for actual loading or clinical interpretation.
References
Similar or alternative tools
- Moment Arm Sign From Axis
Return a signed planar moment under an axis-normal policy.
- Joint Moment Anatomical Axis Token
Transform a moment with a supplied axis sign.