Before subtracting the numbers
A matching metric name is not enough. Check the view, landmark placement, measurement method and scale. A different camera position, trunk rotation or point location can change the result. Assess capture quality before interpreting a difference.
- Select the same metric and view.
- Read the measurement method and the origin of the points, including estimates and manual adjustments.
- For distances, check the unit and scale. Pixels are not centimetres.
- Compare capture conditions. Missing setup information limits interpretation.
A synthetic example
A metric reads 8 degrees at the first session and 6 degrees at the second. Latest minus earlier is minus 2 degrees. This describes a numerical change, not proof that pain decreased or treatment succeeded. Which direction is desirable also depends on the metric and individual assessment.
Keep context with the measurement
Record the original goal, daily function, reported symptoms and practitioner interpretation. Completed sessions describe adherence, not treatment outcome by themselves. Practitioner records retain programme versions and follow-up decisions.
How the website compares reports
The comparison checks measurement compatibility. Missing or different capture information leads to an explanation instead of an improvement claim. A text-based screening assessment cannot supply a posture-angle comparison.
Capture comparable photographs · Read a sample report · Photogrammetry validity evidence