biomechanics-validation

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.

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Install this agent skill to your Project

npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/data/biomechanics-validation

SKILL.md

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