majiayu000 Biomechanics Validation
When reviewing jump metrics, validate against these norms:
RSI (Reactive Strength Index)
| Population | RSI Range |
|---|---|
| Recreational | 0.5-1.5 |
| Trained | 1.5-2.5 |
| Elite | 2.5-3.5 |
Flag values > 3.5 as potentially erroneous (measurement or technique issue).
CMJ Jump Height
| Population | Male (cm) | Female (cm) |
|---|---|---|
| Recreational | 25-40 | 20-35 |
| Trained | 40-55 | 35-45 |
| Elite | 55-70+ | 45-55+ |
Ground Contact Time (Drop Jump)
| Range | Interpretation |
|---|---|
| < 100 ms | Likely sensor/detection error |
| 150-250 ms | Optimal reactive strength |
| 250-350 ms | Acceptable, technique improvement possible |
| > 400 ms | Technique issue or fatigue |
Flight Time
| Jump Type | Typical Range | Flag If |
|---|---|---|
| CMJ | 400-600 ms | > 800 ms |
| Drop Jump | 350-550 ms | > 700 ms |
Triple Extension (CMJ)
All three joints should approach full extension at takeoff:
- Hip: > 160° (optimal: 170-180°)
- Knee: > 160° (optimal: 170-180°)
- Ankle: > 130° (plantar flexion)
Countermovement Depth (CMJ)
| Depth | Interpretation |
|---|---|
| < 20 cm | Shallow - may limit power generation |
| 20-40 cm | Optimal range |
| > 50 cm | Deep - may indicate technique issue |
Validation Response Format
When validating metrics, provide:
- Status: Normal / Warning / Error
- Value: The actual metric value
- Expected Range: Population-appropriate range
- Interpretation: Coaching-friendly explanation
- Recommendation: If outside norms, suggest next steps
Example Validation
RSI: 2.8
Status: Normal (Elite range)
Expected: 2.5-3.5 for elite athletes
Interpretation: Excellent reactive strength capability
Ground Contact Time: 85 ms
Status: Warning
Expected: 150-250 ms optimal
Interpretation: Unusually short - likely detection error
Recommendation: Review debug video for takeoff/landing detection accuracy