When a subject has more than one session in the same module, QOOM compares the most recent session to the previous one and classifies change per metric.
Classifications
- Improving — the metric moved in the direction that corresponds to better performance, by more than the stability threshold.
- Stable — the metric changed by less than the stability threshold.
- Declining — the metric moved in the direction that corresponds to worse performance, by more than the stability threshold.
- Insufficient data — not enough history to classify, or the metric was excluded (e.g. value was outside plausible range).
Stability threshold
By default, a change of less than 3% is classified as stable. For some metrics (symmetry index, knee valgus, limb symmetry index), a smaller threshold is used because small changes in these metrics are more meaningful.
Direction semantics
The direction of "improvement" depends on the metric:
- Higher is better — gait speed, hop distance, jump height, RSI, LSI
- Lower is better — symmetry index, knee valgus, contact time, trunk lean
- Range — cadence, squat tempo, landing knee flexion, concentric/eccentric duration (middle of the range is better)
Overall trend
An overall module trend is derived from the per-metric classifications:
- Improving if more metrics improved than declined.
- Declining if more metrics declined than improved.
- Stable otherwise.
How to use trend information
- Trends are more meaningful than single-session grades.
- Consistent improvement over 3+ sessions is a stronger signal than a single improvement.
- One declining session in isolation may reflect measurement variability — compare multiple sessions.
- Always interpret trends in the context of what you changed in the subject's program between sessions.
What trends do not tell you
- Why the metric changed. Could be real change, pacing, calibration, clothing, lighting, or measurement noise.
- Whether the change is clinically significant.
- Causality. A subject who added squats between sessions may or may not have improved because of the squats.
Use trends as one input into your professional assessment of the subject's progress.