Current weighting
Grip-strength version: 25% grip strength, 35% 5x sit-to-stand, 20% general baseline fatigue, 20% post-5x sit-to-stand fatigue.
No-grip version: 50% 5x sit-to-stand, 25% general baseline fatigue, 25% post-5x sit-to-stand fatigue.
Upper and lower body sub-scores
The overall Measured Function Score stays exactly the same. The new regional sub-scores are secondary views built from the same inputs.
- Upper body score uses grip as the main anchor, then adds a smaller share of baseline fatigue and a very small share of post-test fatigue.
- Lower body score uses 5x sit-to-stand as the main anchor, then adds baseline fatigue and a larger share of post-test fatigue because the fatigue challenge comes from the standing task.
- With grip protocol: upper body = 62.5% grip, 25% baseline fatigue, 12.5% post-test fatigue.
- Lower body = 58.3% sit-to-stand, 16.7% baseline fatigue, 25% post-test fatigue.
- No-grip protocol: upper body is intentionally not estimated, because there is no direct upper-body performance measure in that version.
Current sex-specific scaling
The objective measures are no longer scored on one shared curve.
- Grip uses sex-specific low, solid, and strong thresholds.
- Grip now uses a dominant-hand anchor plus an optional bilateral consistency adjustment from the non-dominant hand.
- Grip uses a higher practical ceiling for males than females.
- Sit-to-stand uses a shared 3-second top benchmark with sex-specific floor values so the lower end is still scaled appropriately by sex.
Why sit-to-stand gets the largest weight
- It is the best whole-body functional output in this bundle rather than a single-limb strength signal.
- It reflects lower-body power, transfer ability, coordination, and practical performance.
- It is more directly aligned with day-to-day function than grip strength alone.
- It has stronger direct relevance to mitochondrial and mobility-focused functional assessment than a pure hand measure.
Why grip strength is still included at 30%
- It is fast, objective, low-cost, and easy to standardize.
- It contributes a strength or physiologic reserve signal that sit-to-stand does not fully capture.
- It is strongly supported in broader outcomes literature, even if the mitochondrial-specific evidence base is thinner than for performance testing.
Why fatigue stays at 30%
- Fatigue is central to how patients actually experience low energy.
- General baseline fatigue captures the person's usual lived burden before testing starts.
- Post-test fatigue adds an exertional-cost signal that static performance alone can miss.
- Together they balance objective performance with both baseline and provoked symptom burden.
Why not use 40 / 35 / 25
That older version made grip strength the largest component. We moved away from that because it probably over-weighted a localized strength measure relative to whole-body function and lived fatigue burden.
Why not equal weights
Equal weights are very defensible when data are limited, but this version intentionally gives a modest edge to sit-to-stand because it is the strongest practical whole-body function measure in the bundle.
What would make this fully evidence-based
These weights are still expert-style heuristic weights. The best future version would learn the weights from your own dataset by fitting them against clinician assessment, Energy Score agreement, and future functional outcomes.