Data Interpretation Guide

This guide shows exactly how to interpret our data at the highest level.

Pre‑Check: Make Sure the Overlay Is Optimal

• Record with good background contrast (avoid blinding backlight or very dark scenes).
• Don’t over‑trim the video at the start/end or let video run too long at the end; include the full throw and a clean finish.
• If tracking looks off, try a better capture; if it persists, file a support ticket. Tech is robust, but like any first‑of‑kind system, occasional recalibration helps.

Overlay Video Review

Posture at Key Phases‍

• From foot strike through ball release, keep the chest stacked over the hips.
• Avoid early forward flexion or a collapsed back leg (knees caving in) at foot strike.

Arm Tracer Path

• Might be small inaccuracies in the first ~¼ of the throw (ball can occlude tracking of the wrist); last ~¾ should always be clean.
• From layback → release, the slot should stay level. A big rise/drop suggests a changing slot.
• In the pull phase, the slot can start lower and settle to level, but never start high (elbow above shoulder).

Peak Arm Speed (red marker in the tracer)

• Ideal: peaks right at or just before ball release (acceleration through release).
• If peak occurs early, a common cause is strength limitation so the body slows itself to protect the arm/shoulder.

Sequencing Bar + Timeline (bottom)

• Desired order: 1) foot strike → 2) peak hip speed → 3) peak torso speed → 4) peak elbow extension velocity.
• Two common issues to watch for:
  
  • Hips slow to rotate after foot strike (pushing/sliding, not rotating).
  • Peaks stacked too close together (little/no delay between hips and torso).

Right‑Side Metric Tiles (quick snapshot)

• Max shoulder external rotation (MER)
• Peak arm speed
• Peak hip–shoulder separation velocity
• Release time

Page 1 (Still Frames + 4 Key Metrics)

Still Frames (4 images)

• Foot strike, back hip termination, torso termination, maximum elbow extension.
• Use these clean frames (without markers) to verify: posture, base width, and weight shift.

Four Key Metrics

Compare Speeds Together

• High rotation speeds + low arm speed → energy not offloading to the arm (mechanical transfer issue or strength gap).
• High arm speed + low rotation speeds → arm is the workhorse → increased stress/injury risk.

Color Bars Under Tiles

• Every tile uses a red / yellow / green band for context (lower / mid / upper third).
• Green is generally “good” for that metric (useful anchor for all tiles in the report).

Page 2 (Sequencing + Scores + Additional Metrics)

Sequencing Graph (velocity y‑axis, reference lines at foot strike / MER / release)

• Confirm order and spacing of peak hip, peak torso, and peak elbow extension events.
• A small but distinct gap from hips → torso → arm indicates efficient transfer.
• Red flags: hips rotate late after foot strike; peaks stacked together.

Scores

• Sequencing Score: how efficiently you transfer power throughout the throw.
• Overall Throw Score: a general view of how optimized your current throwing motion is (i.e. 76% means that throw was 76% of your potential).
  
  • Not a QB ranking; compare you vs. you over time.
• Acceleration Score: how effectively you are accelerating and generating speed during the motion.
• Deceleration Score: how well you control your speeds and brace the acceleration phase.
• Velocity Efficiency Score: how efficient your motion is when genarating and controlling velocity/power.

Additional Page‑2 Metrics‍

• Max Shoulder External Rotation (MER, °): the maximum amount of layback in the throwing shoulder during the throw.
• Peak Hip–Shoulder Separation Velocity (°/s): how fast your separate your hips and torso.
• Stride Length (% of height): the size of your base relative to height (it’s relative to height, not just “how far you step”). Example, 48% means base is 48% of your height.

Page 3 (Joint Angles in Degrees)

All angle graphs share the same reference lines: foot strike, MER, ball release.

Joint Angle Graphs Overview

Elbow Extension

Shoulder External Rotation

Shoulder Abduction

Shoulder Horizontal Abduction

Lead Knee Flexion

Trunk & Pelvis Rotation

Hip-Shoulder Separation

Trunk Flexion

Page 4 (Joint Velocities in °/s)

Joint Velocity Graphs Overview

Elbow Extension

Shoulder Horizontal Abduction

Shoulder Abduction

Shoulder External Rotation

Lead Knee Flexion

Trunk & Pelvis Rotation

Hip-Shoulder Separation

Trunk Flexion

Page 5 (Tabular Data: Exact Angles by Phase + Min/Max Velocities)

Angles & min/max velocities reported at: pre‑throw, foot plant, MER, ball release, follow‑through.

Page 6 (Stride Mechanics + Timing/Speed + Scores Recap)

Motion Phases (What to Look For in the Data)

Pull Phase (hand separation → start of steady rise in shoulder external rotation)

• On Page 3, mark the start when elbow extension starts (or shoulder abduction/external rotation lines begin moving).
• Mark the end when shoulder external rotation begins its steady increase.
• What to check:
  
  • Scap load should build (shoulder horizontal abduction rising).
  • Shoulder rotation context:
    
    • Internal rotation here is very powerful but lengthens the motion so youmust ensure overall release time stays in a healthy window.
    • External rotation here is quick but often costs velocity later so consider nudging toward neutral if speeds/sequence suffer.
  • Avoid being too long (over‑extended elbow behind body) or too tight (excessive elbow flexion).
  • Abduct the arm away from the body; don’t stay pinned.

Layback Phase (end of pull → MER)

• Confirm a smooth rise in layback without jerks; posture stable; hip–shoulder separation maintained or increased before acceleration.

Acceleration Phase (MER → ball release)

• Peaks should occur in the correct order at strong magnitudes.
• Lead leg should stabilize (avoid racing toward lockout).
• Full elbow extension at release.
• Peak arm speed should be at/near release (early peaks often signal strength gaps).

Big Buckets (Diagnose Primary Issue)

Mobility

• Low MER (often <120°) and/or lack of thoracic extension at MER.
• Work shoulder/T‑spine mobility.

Stretch (Elastic Energy)

• ‍‍Trio: hip–shoulder separation, scap load, MER.
• Most common limitations are scap control and hip–shoulder separation feel (motor patterning).
• Train the pattern (feel), then load it with speed and strength.

Speed

• Low hip, torso, or arm velocities.
• Improve explosive rotation and refine mechanics to raise peak speeds.

Frontside Stability

• Lead knee extension delta from foot strike → release: ~10° fine, 10–15° okay, ~20°+ excessive.
• Absolute at release near 0° (locked) is a major red flag.
• Avoid excessive forward flexion at release; maintain posture to finish with extension.

Strength

• Good sequencing and mobility but speeds remain low → strengthen into the exact positions/ranges you need to access at full speed (throw‑specific strength).

Common Pattern Interpretations (Quick Reference)

• Overall Rotation Speed = hip speed + torso speed
  
  • Higher total → higher velocity potential.
• High rotation speeds + low arm speed → offload/transfer issue or strength limitation.
• High arm speed + low rotation speeds → arm is overworking → stress risk; improve body rotation & sequence.
• High hip speed + low torso speed → usually a hip–shoulder separation maintenance issue (often frontside opening early); occasionally upper‑body rotational strength.
• Early peak arm speed → often strength issue; the system slows early to protect the arm.
• Low stretch metrics (hip–shoulder separation, scap load, layback) → usually scap control and patterning gaps more than raw range of motion issue.