biomechanics-validation

name	biomechanics-validation
description	Validates jump metrics against physiological norms. Use when analyzing CMJ or drop jump results, discussing RSI values, jump heights, ground contact times, or when metrics seem unusual.

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:

1. Status: Normal / Warning / Error
2. Value: The actual metric value
3. Expected Range: Population-appropriate range
4. Interpretation: Coaching-friendly explanation
5. 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