05
N1 Performance Lab
Issue 05
Force-Time CMJ Series · Movement Intelligence
THE
PHASE
MAP
Reading Movement Intelligence from a Single Jump · MB·1 · MB·2
N1 Performance Lab PH
Hawkin Dynamics CMJ Series
Manila, Philippines · 2026
The Architecture
THE SIX PHASES
Every CMJ is the same test. Not every CMJ is the same movement.
01
Weighing
The athlete stands still to establish baseline system weight. Every subsequent calculation depends on this value. The athlete must remain motionless — noise here propagates through the entire force-time curve.
↳ System Weight
02
Unweighting
The athlete begins descending. Ground reaction force drops below bodyweight as the center of mass falls. The athlete builds potential energy — converted to kinetic energy in the braking phase.
↳ Movement Onset · Unweighting Impulse
03
Braking
The athlete arrests the downward movement. Force rises rapidly. Braking RFD — how fast force develops here — is the primary readiness and injury risk signal in the N1 monitoring system. It moves before jump height does.
↳ Braking RFD · Peak Braking Velocity · Avg Braking Force
04
Propulsion
The athlete drives upward from the lowest position. Propulsive impulse — not peak force — determines how much mechanical work transfers into flight. The braking-to-propulsion conversion efficiency lives here.
↳ Propulsive Impulse · Peak Force · Avg Propulsive Force
05
Flight
The airborne phase. Jump height is calculated from takeoff velocity — not flight time. It is the last variable to shift under fatigue. When it drops, the preceding phase signals have already been visible for 1–3 weeks.
↳ Jump Height · Takeoff Velocity
06
Landing
Ground contact through full stop. Landing force asymmetry flags unequal limb loading on impact — a separate injury signal from the propulsive asymmetry measured in Phase 4. A controlled landing requires hip, knee, and ankle flexion to dissipate force.
↳ L/R Landing Force · Peak Landing Force
Braking Phase — Phase 3
Phase 3
Eccentric-to-Concentric Transition
The braking phase is where the body arrests downward momentum and converts it into stored elastic energy. Speed of force development here — braking RFD — determines how effectively that energy transfers into Phase 4 propulsion.
Primary Signal
Braking
RFD
N/s — Rate of Force Development
Drops before jump height drops. Drops before RPE rises. The earliest mechanical indicator of neuromuscular fatigue and soft tissue stress in the N1 CMJ monitoring system.
Phase 3 → Phase 4 Conversion
Braking →
Propulsion
The Transition Window
How much of the Phase 3 braking impulse converts into Phase 4 propulsive output? Athletes with high braking RFD but low propulsive impulse are loading efficiently but losing energy at the transition. That is MB·1's pattern.
Asymmetry Flag
>10%
Bilateral Asymmetry Threshold
When left-to-right force distribution in the Phase 3 braking phase exceeds 10%, a bilateral review is triggered. At this threshold, one limb is compensating for the other. That is MB·2's pattern. Phase 6 landing force confirms the same limb preference on impact.
MB·1 · 178cm
Middle Blocker · [Organization] Women's Volleyball
CONVERSION
FAILURE
Braking phase loads correctly. The eccentric demand is met. Force development is adequate. But at the braking-to-propulsion transition, the energy transfer breaks down. Propulsive impulse is lower than the braking input predicts. The jump underperforms its own mechanical setup.
Braking RFD
Within Norm
Propulsive Impulse
↓ Below Predicted
Asymmetry
Bilateral
MB·2 · 180cm
Middle Blocker · [Organization] Women's Volleyball
COMPENSATORY
LOADING
Braking phase shows progressive left-to-right asymmetry across the monitoring period. The dominant limb is absorbing load the non-dominant limb is no longer contributing equally. Jump height is maintained — the compensation is working. The tissue loading is not sustainable.
Braking RFD
Asymmetric ↑ DOM
Propulsive Impulse
Maintained
Asymmetry
>10% — Flagged
The Mechanical Event
THE TRANSITION
IS WHERE
ATHLETES
DIFFER.
P3 → P4
Braking → Propulsion
The Phase 3-to-Phase 4 transition is the moment the movement reverses direction. How fast an athlete can reverse — and how much of the Phase 3 braking impulse survives that reversal — defines their stretch-shortening cycle efficiency. Two athletes with identical jump heights can have radically different transition profiles. That difference is invisible without phase-level data.
SSC
Stretch-Shortening Cycle
The SSC is the body's elastic energy recovery mechanism. Phase 3 braking loads the spring. Phase 4 propulsion releases it. When the transition is efficient, Phase 4 output exceeds what pure concentric strength alone could produce. When the transition leaks — through timing errors, fatigue, or asymmetry — the spring loses energy before release. That loss shows up as a gap between Phase 3 braking RFD and Phase 4 propulsive impulse on the force-time curve.
Session-Over-Session
HOW THE
PHASE MAP
SHIFTS
UNDER LOAD.
The phase fingerprint does not stay static across a competitive season. Fatigue, adaptation, and injury accumulation all alter the shape of the force-time curve — in a specific sequence.
The sequence is predictable. Braking RFD moves first. Propulsive impulse follows. Jump height moves last. Monitoring only jump height is monitoring the end of the sequence — after every earlier signal has already fired.
Week 1–2 — Braking RFD Decline
First signal. Neuromuscular fatigue reduces force development rate in the braking phase. Undetectable from jump height alone. The athlete feels fine. The curve has already moved.
Week 2–3 — Propulsive Impulse Drop
Second signal. The braking deficit propagates forward. The transition zone leaks more energy. Propulsive output begins to fall. Jump height starts to show minor variance — still within noise for most monitoring systems.
Week 3+ — Jump Height Drops
Last signal. By the time jump height drops measurably, the athlete has been accumulating mechanical risk for 1–3 weeks. The injury window has been open since Week 1.
The Infrastructure Argument
MOVEMENT
INTELLIGENCE
REQUIRES
A TREND.
Single Session
Produces a snapshot. Braking RFD is 6,200 N/s. Is that good? Compared to what? Without a personal baseline and without a trend direction, a single number is close to meaningless for readiness decisions.
Weekly Monitoring
Produces a trend. Braking RFD was 7,400 → 6,800 → 6,200 N/s across three sessions. That direction — not the number — is the signal. The athlete's personal baseline makes the decline readable. The trend makes it actionable.
Season-Long Dataset
Produces movement intelligence. Load-injury correlations become visible. Phase fingerprints under competition block vs. recovery week become distinguishable. Training prescription can be derived from the curve — not just from feel.
Series Arc
THE CMJ
SERIES
CONTINUES.
A01 through A05 have mapped the force-time curve — phase by phase, signal by signal. The braking phase. The propulsive phase. The transition. The fatigue sequence. The movement fingerprint.
The next question is not what happens inside the jump. It is where the athlete sits on the force-velocity spectrum — and what that means for training prescription.
Coming — Article 06
THE FORCE-VELOCITY
PROFILE
Every athlete occupies a position on the force-velocity curve — from force-dominant to velocity-dominant. That position determines the training stimulus that produces the most adaptation. The CMJ identifies it. Article 06 explains how to read it and what to do with it.
05
N1 Performance Lab · Issue 05
THE
CURVE
SPEAKS
FIRST.
Jump height is the last metric to move. By the time it drops, the phase map has already been signaling for weeks.
Source: Hawkin Dynamics CMJ · [Organization] Women's Volleyball
N1 Performance Lab PH · Manila, Philippines · 2026
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