Glenohumeral Internal Rotation Deficit GIRD18° Threshold
Matched independently measured IRloss, nondominant minus dominant, screened against explicitly nominal18 degrees. Total arc, bony adaptation, protocol, history and uncertainty remain essential; no GIRDdiagnosis or treatment.
Description
Internal-rotation deficit compares matched dominant and nondominant shoulder measurements.
Internal-rotation deficit compares matched dominant and nondominant shoulder measurements.1
A nominal eighteen-degree flag is an arithmetic screen rather than a diagnosis. Use this tool to calculate the stated observation or conditional model from supplied measurements.
When to use Glenohumeral Internal Rotation Deficit GIRD18° Threshold
Use this tool to calculate the stated observation or conditional model from supplied measurements. Establish the measurement protocol, instrument or reference edition, matching units and observation context.
How to use Glenohumeral Internal Rotation Deficit GIRD18° Threshold and understand its results
- Establish the measurement protocol, instrument or reference edition, matching units and observation context.
- Enter observedDominantInternalRotationDegrees, observedNondominantInternalRotationDegrees, using the field meanings and rules below, then run the tool.
- Read result.signedInternalRotationDeficitDegrees, result.atOrAboveNominalEighteenDegrees. Interpret each field using the units, signs and evidence rules below.
- If input validation fails, correct the reported field and run again. Before applying a successful result, check the stated reference scope, units, assumptions and any retained unknown evidence.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedDominantInternalRotationDegrees | Observed dominant internal rotation degrees | number | Required |
| observedNondominantInternalRotationDegrees | Observed nondominant internal rotation degrees | number | Required |
Require nonnegative finite dominant and nondominant internal-rotation angles. Subtract dominant from nondominant and flag difference≥18 degrees. Negative differences remain negative; there is no upper-angle bound, total-arc assessment or injury diagnosis.
signedDeficitDegrees=nondominantDegrees−dominantDegrees; nominalFlag=(deficit≥18) Apply the field units and exact ordering, boundary and evidence rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Structured result containing the calculation or selected reference fields below | object |
| result.signedInternalRotationDeficitDegrees | Signed Internal Rotation Deficit Degrees; use the units, sign convention and calculation stated above | number |
| result.atOrAboveNominalEighteenDegrees | Whether the signed deficit is at least the fixed 18-degree comparison | boolean |
{
"input": {
"observedDominantInternalRotationDegrees": 40,
"observedNondominantInternalRotationDegrees": 60
},
"output": {
"result": {
"signedInternalRotationDeficitDegrees": 20,
"atOrAboveNominalEighteenDegrees": true
}
}
}Limitations and assumptions
A nominal eighteen-degree flag is an arithmetic screen rather than a diagnosis. Results depend on the independently established measurement basis and the exact model assumptions above.
Every listed input requires an explicit value. Unexpected fields, incorrect value types, nonfinite numbers and sparse numeric arrays fail validation; tool-specific bounds and alignment rules apply as described above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful calculation that reports a false comparison or retains unknown evidence.
Alternative or Complementary methods
Use Hop Test Limb Symmetry Index≥90% Criterion to examine a related aspect: Hop limb-symmetry index compares involved and matched uninvolved performance.
Use Functional Reach Inches Fall Risk Lookup where its separate inputs and scope apply: Functional reach depends on posture, procedure and reference population.
References
Similar or alternative tools
- Hop Test Limb Symmetry Index≥90% Criterion
Hop limb-symmetry index compares involved and matched uninvolved performance.
- Functional Reach Inches Fall Risk Lookup
Functional reach depends on posture, procedure and reference population.