What we measure

Every metric ForceMate calculates from PlateMate, GroinMate and CableMate tests: what it means, its unit and, for derived metrics, the formula behind it. For jump metrics we also list what VALD and Hawkin Dynamics call the same metric, checked against their exports of the same jumps.

97metrics · 223incl. left/right

Jump Performance Primary outcome measures of jump performance 7 metrics

Jump Height (ft) m

Jump Height by Flight Time (FT)

\frac{g \, t_{\text{flight}}^2}{8}

$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{flight}}$: Flight time

Jump Height (ni) m

Jump Height by Net Impulse (NI)

Same as: Hawkin Dynamics: Jump Height

\frac{v_{\text{takeoff}}^2}{2g}

$v_{\text{takeoff}}$: Velocity at takeoff
$g$: Gravitational acceleration (9.81 m/s²)

Takeoff Velocity m/s

Vertical velocity of the center of mass at takeoff.

Same as: VALD: Vertical Velocity at Takeoff

RSI (Flight Time)

Flight time divided by contact time (DJ) or by time to takeoff (CMJ/SJ).

Same as: VALD: Flight Time:Contraction Time; Hawkin Dynamics: RSI

\frac{t_{\text{flight}}}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

RSI Modified

Jump height divided by contact time (DJ) or by time to takeoff (CMJ/SJ). Uses the net-impulse jump height when available.

Same as: Hawkin Dynamics: mRSI

Jump Momentum kg·m/s

The momentum generated during the jump, calculated as the product of body mass and takeoff velocity.

m \cdot v_{\text{takeoff}}

$m$: Body mass
$v_{\text{takeoff}}$: Velocity at takeoff

Displacement Depth m

Maximum depth of the countermovement phase, representing how far the center of mass descends before the propulsive phase begins.

Same as: VALD: Countermovement Depth; Hawkin Dynamics: Countermovement Depth

Impulse Metrics Impulse metrics during braking and propulsive phases 6 metrics

Net Impulse N·s L / R

The total impulse (bodyweight subtracted) applied during the braking+propulsive phase

Net Eccentric Impulse N·s L / R

Net impulse over the full eccentric phase (unweighting + braking combined). Because the athlete starts and ends this phase at rest, the two sub-phases largely cancel — values near zero are normal.

\left| \int_{\text{eccentric}} (F - BW)\,dt \right|

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Propulsive Impulse N·s L / R

Net impulse (force minus body weight) from the lowest position to takeoff. Also called concentric impulse.

Same as: VALD: Concentric Impulse; Hawkin Dynamics: Propulsive Net Impulse
Not the same as: Hawkin Dynamics: Propulsive Impulse

\int_{\text{propulsive}} (F - BW)\,dt

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Rel. Propulsive Impulse N·s/kg

Net impulse during the propulsive phase relative to body mass

Same as: Hawkin Dynamics: Relative Propulsive Net Impulse
Not the same as: Hawkin Dynamics: Relative Propulsive Impulse

\frac{J_{\text{propulsive}}}{m}

$J$: Impulse
$m$: Body mass

Braking Impulse N·s L / R

Net impulse (force minus body weight) during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Net Eccentric Impulse' for the full eccentric phase.

Not the same as: Hawkin Dynamics: Braking Impulse; Hawkin Dynamics: Braking Net Impulse (see Deceleration Impulse)

Deceleration Impulse N·s

Net impulse (force minus body weight) from Eccentric Peak Velocity (EPV) to the lowest point.

Same as: VALD: Eccentric Deceleration Impulse; Hawkin Dynamics: Braking Net Impulse

Force Metrics Force measurements during various phases and conditions 16 metrics

Peak Force N L / R

The peak instantaneous force during the entire jump

Same as: VALD: Takeoff Peak Force

Min Unweight Force N

The minimum force measured during the unweighting phase

Same as: VALD: Minimum Eccentric Force

Rel. Min Unweight Force BW

Minimum force during the unweighting phase, as a multiple of body weight.

\frac{F_{\text{min unweighting}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Peak Braking Force N L / R

Peak force during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Peak Eccentric Force' for the full eccentric phase.

Avg Braking Force N L / R

Average force during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Avg Deceleration Force' for the deceleration phase only and 'Avg Eccentric Force' for the full eccentric phase.

Same as: VALD: Eccentric Mean Braking Force
Not the same as: Hawkin Dynamics: Avg. Braking Force (see Avg Deceleration Force)

Avg Deceleration Force N

Average force from Eccentric Peak Velocity (EPV) to the lowest point. Higher than 'Avg Braking Force' because it leaves out the early part of braking, where force is still close to body weight.

Same as: VALD: Eccentric Mean Deceleration Force; Hawkin Dynamics: Avg. Braking Force

Rel. Avg Deceleration Force N/kg

Avg Deceleration Force relative to body mass.

\frac{\bar{F}_{\text{deceleration}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Avg Eccentric Force N L / R

Average force over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Same as: VALD: Eccentric Mean Force

Peak Eccentric Force N L / R

Peak force over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Same as: VALD: Eccentric Peak Force

Avg Propulsive Force N L / R

The average force during the propulsive phase

Same as: VALD: Concentric Mean Force

Rel. Avg Propulsive Force N/kg

Average force during the propulsive phase relative to body mass

Same as: VALD: Concentric Mean Force / BM

\frac{\bar{F}_{\text{propulsive}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Peak Propulsive Force N L / R

The peak instantaneous force during the propulsive phase

Same as: VALD: Concentric Peak Force

Relative Peak Force BW

Peak force output expressed as multiples of body weight

\frac{F_{\text{peak}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Force @ Peak Power N

Force at the moment of peak power.

Force @ Min Displacement N

Ground reaction force at the lowest point of the countermovement.

Same as: VALD: Force at Zero Velocity

Rel. Force @ Min Displacement BW

Force at the lowest point of the countermovement, as a multiple of body weight.

\frac{F_{\text{min displacement}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Power Power output throughout the jump 11 metrics

Peak Braking Power W L / R

Peak power during the braking phase only (negative value). See 'Peak Eccentric Power' for the full eccentric phase as an absolute value.

Avg Braking Power W L / R

Average power during the braking phase only (negative value). See 'Avg Eccentric Power' for the full eccentric phase as an absolute value.

Not the same as: Hawkin Dynamics: Avg. Braking Power

Braking Work J L / R

Work done during the braking phase only (negative value). See 'Eccentric Work' for the full eccentric phase as an absolute value.

Peak Eccentric Power W L / R

Peak power over the full eccentric phase (unweighting + braking), reported as an absolute value.

Same as: VALD: Eccentric Peak Power

Avg Eccentric Power W L / R

Average power over the full eccentric phase (unweighting + braking), reported as an absolute value.

Same as: VALD: Eccentric Mean Power

Eccentric Work J L / R

Work done over the full eccentric phase (unweighting + braking), reported as an absolute value.

\left| \overline{F \cdot v} \cdot \Delta t_{\text{eccentric}} \right|

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Propulsive Power W L / R

The maximum power output during the propulsive phase

Same as: VALD: Peak Power

Avg Propulsive Power W L / R

The average power output during the propulsive phase

Same as: VALD: Concentric Mean Power

Propulsive Work J L / R

The total work done during the propulsive phase

\overline{F \cdot v} \cdot \Delta t_{\text{propulsive}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Power W

The peak instantaneous power during the entire jump

Same as: Hawkin Dynamics: Peak Propulsive Power

Relative Peak Power W/kg

Peak power output expressed as watts per kilogram of body weight

Same as: VALD: Peak Power / BM; Hawkin Dynamics: Peak Relative Propulsive Power

\frac{P_{\text{peak}}}{m}

$P$: Power (F · v)
$m$: Body mass

Velocity Velocity throughout the jump 8 metrics

Min Braking Velocity m/s

The minimum velocity during the braking phase

Avg Braking Velocity m/s

The average velocity during the braking phase

Not the same as: Hawkin Dynamics: Avg. Braking Velocity

Min Eccentric Velocity m/s

Fastest downward velocity (most negative value) in the eccentric phase, also called Eccentric Peak Velocity (EPV). It marks the start of the deceleration phase.

Same as: VALD: Eccentric Peak Velocity; Hawkin Dynamics: Peak Braking Velocity

Avg Eccentric Velocity m/s

Average velocity over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Peak Propulsive Velocity m/s

The highest velocity reached during the propulsive phase

Same as: VALD: Concentric Peak Velocity; Hawkin Dynamics: Peak Velocity

Avg Propulsive Velocity m/s

The average velocity during the propulsive phase

Same as: VALD: Concentric Mean Velocity

Peak Velocity m/s

The peak instantaneous velocity during the propulsion phase

Same as: VALD: Concentric Peak Velocity

Velocity @ Peak Power m/s

Velocity at the moment of peak power.

Force Development Rate of force development and force application speed 5 metrics

Avg RFD N/s L / R

Average rate of force development: the rise in force up to peak force, divided by the time to peak force.

Avg Braking RFD N/s L / R

The average slope of force during the braking phase

Same as: VALD: Eccentric Braking RFD
Not the same as: Hawkin Dynamics: Braking RFD (see Deceleration RFD)

Deceleration RFD N/s L / R

Rate of force development in the deceleration phase, from Eccentric Peak Velocity (EPV) to the lowest point. Similar to 'Braking RFD' or 'Load' in other systems.

Same as: VALD: Eccentric Deceleration RFD; Hawkin Dynamics: Braking RFD

\frac{F_{\text{braking end}} - F_{v_{\min}}}{t_{\text{braking end}} - t_{v_{\min}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript
$v_{\min}$: Lowest (most downward) velocity, where deceleration starts

Eccentric RFD N/s L / R

Rate of force development during the eccentric phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Propulsive RFD N/s L / R

Rate of force development during the propulsive phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

P1/P2 Analysis Analysis of early vs late propulsive phase characteristics 20 metrics

P1 Impulse N·s L / R

Impulse generated during the first half of the propulsive phase (early triple-flexed position). Represents the first 50% of propulsive impulse, typically when the athlete is in a deeper squat position.

P2 Impulse N·s L / R

Impulse generated during the second half of the propulsive phase (to triple-extension position). Represents the final 50% of propulsive impulse, typically when the athlete is extending to takeoff.

P1 Duration s

Time duration of the first half of the propulsive phase. Indicates how quickly the athlete generates the first 50% of propulsive impulse from the triple-flexed position.

P2 Duration s

Time duration of the second half of the propulsive phase. Indicates how quickly the athlete generates the final 50% of propulsive impulse moving into triple-extension.

P1 Avg Force N

Average force during the first half of the propulsive phase. Indicates force production capability in the deep squat position.

P2 Avg Force N

Average force during the second half of the propulsive phase. Indicates force production capability in the extension to takeoff.

P1:P2 Force Ratio

Ratio of average force in P1 to average force in P2. Values above 1.0 indicate stronger force production in the deeper position, while values below 1.0 indicate stronger force production during extension.

\frac{\bar{F}_{P1}}{\bar{F}_{P2}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1:P2 Duration Ratio

Ratio of P1 duration to P2 duration. Values above 1.0 indicate more time spent generating the first half of impulse, while values below 1.0 indicate faster early phase and more time spent in final extension.

\frac{t_{P1}}{t_{P2}}

$t$: Time of the event named in the subscript
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1 Peak Force N

Peak force during early propulsive phase (P1)

P1 Peak Velocity m/s

Peak velocity during early propulsive phase (P1)

P1 Avg Velocity m/s

Average velocity during early propulsive phase (P1)

P1 Peak Power W

Peak power during early propulsive phase (P1)

P1 Avg Power W

Average power during early propulsive phase (P1)

P2 Peak Force N

Peak force during late propulsive phase (P2)

P2 Peak Velocity m/s

Peak velocity during late propulsive phase (P2)

P2 Avg Velocity m/s

Average velocity during late propulsive phase (P2)

P2 Peak Power W

Peak power during late propulsive phase (P2)

P2 Avg Power W

Average power during late propulsive phase (P2)

P1/P2 Velocity Ratio

Ratio of P1 to P2 average velocity, indicating early vs late phase velocity characteristics

\frac{\bar{v}_{P1}}{\bar{v}_{P2}}

$\bar{x}$: Mean value
$v$: Vertical velocity of the center of mass
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1/P2 Power Ratio

Ratio of P1 to P2 average power, indicating early vs late phase power characteristics

\frac{\bar{P}_{P1}}{\bar{P}_{P2}}

$\bar{x}$: Mean value
$P$: Power (F · v)
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Landing Metrics Force absorption and landing mechanics measurements. For Drop Jumps, these reflect the final landing after the rebound jump — not the initial drop off the box. 8 metrics

Peak Landing Force N L / R

The maximum force recorded during the landing phase of the jump. Measures the ability to absorb force upon landing.

Rel. Peak Landing Force BW

Peak landing force as a multiple of body weight.

\frac{F_{\text{peak landing}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Time to Peak Landing Force s L / R

Time from landing contact to peak landing force. Indicates how quickly peak forces are reached during landing.

Avg Landing RFD N/s L / R

Average rate of force development during landing, calculated from bodyweight to peak landing force over time. Indicates landing stiffness.

Landing RFD 0-20ms N/s L / R

Rate of force development during the first 20ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 20\,\text{ms}) - F(t_{\text{landing}})}{20\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-40ms N/s L / R

Rate of force development during the first 40ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 40\,\text{ms}) - F(t_{\text{landing}})}{40\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-60ms N/s L / R

Rate of force development during the first 60ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 60\,\text{ms}) - F(t_{\text{landing}})}{60\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-80ms N/s L / R

Rate of force development during the first 80ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 80\,\text{ms}) - F(t_{\text{landing}})}{80\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Timing Timing related metrics 15 metrics

Time to Peak Force s L / R

Time from the start of the jump to peak force. For SJ it is measured from the start of the propulsive phase, for DJ from ground contact.

Same as: VALD: Movement Start to Peak Force

Unweighting Duration s

Time from the start of movement to minimum force.

Not the same as: Hawkin Dynamics: Unweighting Phase

Braking Duration s

Time from minimum force to the lowest point of the countermovement. Shorter than the full eccentric phase, which also includes unweighting.

Same as: VALD: Braking Phase Duration
Not the same as: Hawkin Dynamics: Braking Phase (see Deceleration Duration)

Deceleration Duration s

Time from Eccentric Peak Velocity (EPV) to the lowest point of the countermovement. This is the later part of the braking phase.

Same as: VALD: Eccentric Deceleration Phase Duration; Hawkin Dynamics: Braking Phase

t_{\text{braking end}} - t_{v_{\min}}

$t$: Time of the event named in the subscript
$v_{\min}$: Lowest (most downward) velocity, where deceleration starts

Propulsive Duration s

Time from the end of the braking phase (when velocity turns positive) to takeoff. Also called concentric time.

Same as: VALD: Concentric Duration; Hawkin Dynamics: Propulsive Phase

Flight Time s

Time spent in the flight phase

Time to Peak Power s L / R

The time from the start of the jump to the moment of peak power output

Same as: VALD: Movement Start to Peak Power

Contraction Time s

Time from movement start to takeoff. For CMJ this covers the eccentric and concentric phases, for SJ only the propulsive phase, and for DJ the time from landing to takeoff.

Same as: Hawkin Dynamics: Time To Takeoff

Time to Takeoff s

Time from the start of movement to takeoff. Indicates the total ground contact time before leaving the ground.

Same as: VALD: Contraction Time

Time to Peak Braking Force s L / R

Time to reach peak force during braking phase, measured from braking start

Time to Peak Braking Power s L / R

Time to reach peak power during braking phase, measured from braking start

Time to Peak Eccentric Force s L / R

Time to reach peak force during eccentric phase, measured from jump start

Time to Peak Eccentric Power s L / R

Time to reach peak power during eccentric phase, measured from jump start

Time to Peak Propulsive Force s L / R

Time to reach peak force during propulsive phase, measured from propulsive start

Time to Peak Propulsive Power s L / R

Time to reach peak power during propulsive phase, measured from propulsive start

System Properties Basic system and timing measurements 1 metric

System weight kg

Measured weight of the user during the weighting phase, just before the jump

Same as: VALD: Bodyweight in Kilograms

Jump Performance Primary outcome measures of jump performance 6 metrics

Jump Height (ft) m

Jump Height by Flight Time (FT)

\frac{g \, t_{\text{flight}}^2}{8}

$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{flight}}$: Flight time

Jump Height (ni) m

Jump Height by Net Impulse (NI)

\frac{v_{\text{takeoff}}^2}{2g}

$v_{\text{takeoff}}$: Velocity at takeoff
$g$: Gravitational acceleration (9.81 m/s²)

Takeoff Velocity m/s

Vertical velocity of the center of mass at takeoff.

RSI (Flight Time)

Flight time divided by contact time (DJ) or by time to takeoff (CMJ/SJ).

\frac{t_{\text{flight}}}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

RSI Modified

Jump height divided by contact time (DJ) or by time to takeoff (CMJ/SJ). Uses the net-impulse jump height when available.

Jump Momentum kg·m/s

The momentum generated during the jump, calculated as the product of body mass and takeoff velocity.

m \cdot v_{\text{takeoff}}

$m$: Body mass
$v_{\text{takeoff}}$: Velocity at takeoff

Impulse Metrics Impulse metrics during braking and propulsive phases 3 metrics

Net Impulse N·s L / R

The total impulse (bodyweight subtracted) applied during the braking+propulsive phase

Propulsive Impulse N·s L / R

Net impulse (force minus body weight) from the lowest position to takeoff. Also called concentric impulse.

\int_{\text{propulsive}} (F - BW)\,dt

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Rel. Propulsive Impulse N·s/kg

Net impulse during the propulsive phase relative to body mass

\frac{J_{\text{propulsive}}}{m}

$J$: Impulse
$m$: Body mass

Force Metrics Force measurements during various phases and conditions 6 metrics

Peak Force N L / R

The peak instantaneous force during the entire jump

Same as: VALD: Takeoff Peak Force

Avg Propulsive Force N L / R

The average force during the propulsive phase

Rel. Avg Propulsive Force N/kg

Average force during the propulsive phase relative to body mass

\frac{\bar{F}_{\text{propulsive}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Peak Propulsive Force N L / R

The peak instantaneous force during the propulsive phase

Same as: VALD: Concentric Peak Force

Relative Peak Force BW

Peak force output expressed as multiples of body weight

\frac{F_{\text{peak}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Force @ Peak Power N

Force at the moment of peak power.

Power Power output throughout the jump 5 metrics

Peak Propulsive Power W L / R

The maximum power output during the propulsive phase

Same as: VALD: Peak Power

Avg Propulsive Power W L / R

The average power output during the propulsive phase

Propulsive Work J L / R

The total work done during the propulsive phase

\overline{F \cdot v} \cdot \Delta t_{\text{propulsive}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Power W

The peak instantaneous power during the entire jump

Relative Peak Power W/kg

Peak power output expressed as watts per kilogram of body weight

Same as: VALD: Peak Power / BM

\frac{P_{\text{peak}}}{m}

$P$: Power (F · v)
$m$: Body mass

Velocity Velocity throughout the jump 4 metrics

Peak Propulsive Velocity m/s

The highest velocity reached during the propulsive phase

Same as: VALD: Concentric Peak Velocity

Avg Propulsive Velocity m/s

The average velocity during the propulsive phase

Peak Velocity m/s

The peak instantaneous velocity during the propulsion phase

Same as: VALD: Concentric Peak Velocity

Velocity @ Peak Power m/s

Velocity at the moment of peak power.

Force Development Rate of force development and force application speed 2 metrics

Avg RFD N/s L / R

Average rate of force development: the rise in force up to peak force, divided by the time to peak force.

Propulsive RFD N/s L / R

Rate of force development during the propulsive phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

P1/P2 Analysis Analysis of early vs late propulsive phase characteristics 20 metrics

P1 Impulse N·s L / R

P2 Impulse N·s L / R

Impulse generated during the second half of the propulsive phase (to triple-extension position). Represents the final 50% of propulsive impulse, typically when the athlete is extending to takeoff.

P1 Duration s

Time duration of the first half of the propulsive phase. Indicates how quickly the athlete generates the first 50% of propulsive impulse from the triple-flexed position.

P2 Duration s

Time duration of the second half of the propulsive phase. Indicates how quickly the athlete generates the final 50% of propulsive impulse moving into triple-extension.

P1 Avg Force N

Average force during the first half of the propulsive phase. Indicates force production capability in the deep squat position.

P2 Avg Force N

Average force during the second half of the propulsive phase. Indicates force production capability in the extension to takeoff.

P1:P2 Force Ratio

\frac{\bar{F}_{P1}}{\bar{F}_{P2}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1:P2 Duration Ratio

\frac{t_{P1}}{t_{P2}}

$t$: Time of the event named in the subscript
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1 Peak Force N

Peak force during early propulsive phase (P1)

P1 Peak Velocity m/s

Peak velocity during early propulsive phase (P1)

P1 Avg Velocity m/s

Average velocity during early propulsive phase (P1)

P1 Peak Power W

Peak power during early propulsive phase (P1)

P1 Avg Power W

Average power during early propulsive phase (P1)

P2 Peak Force N

Peak force during late propulsive phase (P2)

P2 Peak Velocity m/s

Peak velocity during late propulsive phase (P2)

P2 Avg Velocity m/s

Average velocity during late propulsive phase (P2)

P2 Peak Power W

Peak power during late propulsive phase (P2)

P2 Avg Power W

Average power during late propulsive phase (P2)

P1/P2 Velocity Ratio

Ratio of P1 to P2 average velocity, indicating early vs late phase velocity characteristics

\frac{\bar{v}_{P1}}{\bar{v}_{P2}}

$\bar{x}$: Mean value
$v$: Vertical velocity of the center of mass
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1/P2 Power Ratio

Ratio of P1 to P2 average power, indicating early vs late phase power characteristics

\frac{\bar{P}_{P1}}{\bar{P}_{P2}}

$\bar{x}$: Mean value
$P$: Power (F · v)
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Landing Metrics Force absorption and landing mechanics measurements. For Drop Jumps, these reflect the final landing after the rebound jump — not the initial drop off the box. 8 metrics

Peak Landing Force N L / R

The maximum force recorded during the landing phase of the jump. Measures the ability to absorb force upon landing.

Rel. Peak Landing Force BW

Peak landing force as a multiple of body weight.

\frac{F_{\text{peak landing}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Time to Peak Landing Force s L / R

Time from landing contact to peak landing force. Indicates how quickly peak forces are reached during landing.

Avg Landing RFD N/s L / R

Average rate of force development during landing, calculated from bodyweight to peak landing force over time. Indicates landing stiffness.

Landing RFD 0-20ms N/s L / R

Rate of force development during the first 20ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 20\,\text{ms}) - F(t_{\text{landing}})}{20\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-40ms N/s L / R

Rate of force development during the first 40ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 40\,\text{ms}) - F(t_{\text{landing}})}{40\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-60ms N/s L / R

Rate of force development during the first 60ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 60\,\text{ms}) - F(t_{\text{landing}})}{60\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-80ms N/s L / R

Rate of force development during the first 80ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 80\,\text{ms}) - F(t_{\text{landing}})}{80\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Timing Timing related metrics 9 metrics

Time to Peak Force s L / R

Time from the start of the jump to peak force. For SJ it is measured from the start of the propulsive phase, for DJ from ground contact.

Propulsive Duration s

Time from the end of the braking phase (when velocity turns positive) to takeoff. Also called concentric time.

Flight Time s

Time spent in the flight phase

Time to Peak Power s L / R

The time from the start of the jump to the moment of peak power output

Contraction Time s

Time from movement start to takeoff. For CMJ this covers the eccentric and concentric phases, for SJ only the propulsive phase, and for DJ the time from landing to takeoff.

Time to Takeoff s

Time from the start of movement to takeoff. Indicates the total ground contact time before leaving the ground.

Propulsive Start Time s

The time when the propulsive phase begins (when force transitions from braking to propulsive)

Time to Peak Propulsive Force s L / R

Time to reach peak force during propulsive phase, measured from propulsive start

Time to Peak Propulsive Power s L / R

Time to reach peak power during propulsive phase, measured from propulsive start

System Properties Basic system and timing measurements 1 metric

System weight kg

Measured weight of the user during the weighting phase, just before the jump

Same as: VALD: Bodyweight in Kilograms

Jump Performance Primary outcome measures of jump performance 8 metrics

Jump Height (ft) m

Jump Height by Flight Time (FT)

\frac{g \, t_{\text{flight}}^2}{8}

$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{flight}}$: Flight time

Takeoff Velocity m/s

Vertical velocity of the center of mass at takeoff.

Same as: VALD: Vertical Velocity at Takeoff

RSI (Flight Time)

Flight time divided by contact time (DJ) or by time to takeoff (CMJ/SJ).

\frac{t_{\text{flight}}}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

RSI Modified

Jump height divided by contact time (DJ) or by time to takeoff (CMJ/SJ). Uses the net-impulse jump height when available.

RSI Exponential m/s

A drop-jump RSI variant developed by CC Athletics: flight time squared divided by contact time.

\frac{t_{\text{flight}}^2}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

DRI

Dynamic Rebound Index: (Jump Height + Drop Height) / (g × Contact Time²). A drop-height-aware alternative to RSI, comparable across box heights. Developed by Dr. Lance Brooks, Bridgewater State University.

\frac{h + h_{\text{drop}}}{g \, t_{\text{contact}}^2}

$h$: Jump height
$h_{\text{drop}}$: Drop height
$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{contact}}$: Contact time

Drop Height m

The calculated drop height, derived from the touchdown velocity (v²/2g). Typically differs from the nominal box height.

\frac{v_{\text{touchdown}}^2}{2g}

$v_{\text{touchdown}}$: Velocity at touchdown
$g$: Gravitational acceleration (9.81 m/s²)

Jump Momentum kg·m/s

The momentum generated during the jump, calculated as the product of body mass and takeoff velocity.

m \cdot v_{\text{takeoff}}

$m$: Body mass
$v_{\text{takeoff}}$: Velocity at takeoff

Impulse Metrics Impulse metrics during braking and propulsive phases 4 metrics

Net Impulse N·s

The total impulse (bodyweight subtracted) applied during the braking+propulsive phase

Propulsive Impulse N·s L / R

Net impulse (force minus body weight) from the lowest position to takeoff. Also called concentric impulse.

Same as: VALD: Concentric Impulse

\int_{\text{propulsive}} (F - BW)\,dt

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Rel. Propulsive Impulse N·s/kg

Net impulse during the propulsive phase relative to body mass

\frac{J_{\text{propulsive}}}{m}

$J$: Impulse
$m$: Body mass

Braking Impulse N·s L / R

Net impulse (force minus body weight) during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Net Eccentric Impulse' for the full eccentric phase.

Force Metrics Force measurements during various phases and conditions 8 metrics

Peak Braking Force N L / R

Peak force during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Peak Eccentric Force' for the full eccentric phase.

Avg Braking Force N L / R

Avg Propulsive Force N L / R

The average force during the propulsive phase

Same as: VALD: Concentric Mean Force

Rel. Avg Propulsive Force N/kg

Average force during the propulsive phase relative to body mass

\frac{\bar{F}_{\text{propulsive}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Peak Propulsive Force N L / R

The peak instantaneous force during the propulsive phase

Peak Force N

The peak instantaneous force during the entire jump

Relative Peak Force BW

Peak force output expressed as multiples of body weight

\frac{F_{\text{peak}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Force @ Peak Power N

Force at the moment of peak power.

Power Power output throughout the jump 8 metrics

Peak Braking Power W L / R

Peak power during the braking phase only (negative value). See 'Peak Eccentric Power' for the full eccentric phase as an absolute value.

Avg Braking Power W L / R

Average power during the braking phase only (negative value). See 'Avg Eccentric Power' for the full eccentric phase as an absolute value.

Braking Work J L / R

Work done during the braking phase only (negative value). See 'Eccentric Work' for the full eccentric phase as an absolute value.

Peak Propulsive Power W L / R

The maximum power output during the propulsive phase

Avg Propulsive Power W L / R

The average power output during the propulsive phase

Propulsive Work J L / R

The total work done during the propulsive phase

\overline{F \cdot v} \cdot \Delta t_{\text{propulsive}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Power W

The peak instantaneous power during the entire jump

Not the same as: VALD: Peak Power

Relative Peak Power W/kg

Peak power output expressed as watts per kilogram of body weight

\frac{P_{\text{peak}}}{m}

$P$: Power (F · v)
$m$: Body mass

Velocity Velocity throughout the jump 6 metrics

Min Braking Velocity m/s

The minimum velocity during the braking phase

Avg Braking Velocity m/s

The average velocity during the braking phase

Peak Propulsive Velocity m/s

The highest velocity reached during the propulsive phase

Same as: VALD: Concentric Peak Velocity

Avg Propulsive Velocity m/s

The average velocity during the propulsive phase

Same as: VALD: Concentric Mean Velocity

Peak Velocity m/s

The peak instantaneous velocity during the propulsion phase

Same as: VALD: Concentric Peak Velocity

Velocity @ Peak Power m/s

Velocity at the moment of peak power.

Force Development Rate of force development and force application speed 2 metrics

Avg Braking RFD N/s L / R

The average slope of force during the braking phase

Propulsive RFD N/s L / R

Rate of force development during the propulsive phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

P1/P2 Analysis Analysis of early vs late propulsive phase characteristics 20 metrics

P1 Impulse N·s L / R

P2 Impulse N·s L / R

Impulse generated during the second half of the propulsive phase (to triple-extension position). Represents the final 50% of propulsive impulse, typically when the athlete is extending to takeoff.

P1 Duration s

Time duration of the first half of the propulsive phase. Indicates how quickly the athlete generates the first 50% of propulsive impulse from the triple-flexed position.

P2 Duration s

Time duration of the second half of the propulsive phase. Indicates how quickly the athlete generates the final 50% of propulsive impulse moving into triple-extension.

P1 Avg Force N

Average force during the first half of the propulsive phase. Indicates force production capability in the deep squat position.

P2 Avg Force N

Average force during the second half of the propulsive phase. Indicates force production capability in the extension to takeoff.

P1:P2 Force Ratio

\frac{\bar{F}_{P1}}{\bar{F}_{P2}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1:P2 Duration Ratio

\frac{t_{P1}}{t_{P2}}

$t$: Time of the event named in the subscript
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1 Peak Force N

Peak force during early propulsive phase (P1)

P1 Peak Velocity m/s

Peak velocity during early propulsive phase (P1)

P1 Avg Velocity m/s

Average velocity during early propulsive phase (P1)

P1 Peak Power W

Peak power during early propulsive phase (P1)

P1 Avg Power W

Average power during early propulsive phase (P1)

P2 Peak Force N

Peak force during late propulsive phase (P2)

P2 Peak Velocity m/s

Peak velocity during late propulsive phase (P2)

P2 Avg Velocity m/s

Average velocity during late propulsive phase (P2)

P2 Peak Power W

Peak power during late propulsive phase (P2)

P2 Avg Power W

Average power during late propulsive phase (P2)

P1/P2 Velocity Ratio

Ratio of P1 to P2 average velocity, indicating early vs late phase velocity characteristics

\frac{\bar{v}_{P1}}{\bar{v}_{P2}}

$\bar{x}$: Mean value
$v$: Vertical velocity of the center of mass
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1/P2 Power Ratio

Ratio of P1 to P2 average power, indicating early vs late phase power characteristics

\frac{\bar{P}_{P1}}{\bar{P}_{P2}}

$\bar{x}$: Mean value
$P$: Power (F · v)
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Landing Metrics Force absorption and landing mechanics measurements. For Drop Jumps, these reflect the final landing after the rebound jump — not the initial drop off the box. 8 metrics

Peak Landing Force N L / R

The maximum force recorded during the landing phase of the jump. Measures the ability to absorb force upon landing.

Rel. Peak Landing Force BW

Peak landing force as a multiple of body weight.

\frac{F_{\text{peak landing}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Time to Peak Landing Force s L / R

Time from landing contact to peak landing force. Indicates how quickly peak forces are reached during landing.

Avg Landing RFD N/s L / R

Average rate of force development during landing, calculated from bodyweight to peak landing force over time. Indicates landing stiffness.

Landing RFD 0-20ms N/s L / R

Rate of force development during the first 20ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 20\,\text{ms}) - F(t_{\text{landing}})}{20\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-40ms N/s L / R

Rate of force development during the first 40ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 40\,\text{ms}) - F(t_{\text{landing}})}{40\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-60ms N/s L / R

Rate of force development during the first 60ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 60\,\text{ms}) - F(t_{\text{landing}})}{60\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-80ms N/s L / R

Rate of force development during the first 80ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 80\,\text{ms}) - F(t_{\text{landing}})}{80\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Timing Timing related metrics 9 metrics

Flight Time s

Time spent in the flight phase

Time to Peak Power s

The time from the start of the jump to the moment of peak power output

Time to Peak Force s

Time from the start of the jump to peak force. For SJ it is measured from the start of the propulsive phase, for DJ from ground contact.

Contraction Time s

Time from movement start to takeoff. For CMJ this covers the eccentric and concentric phases, for SJ only the propulsive phase, and for DJ the time from landing to takeoff.

Time to Takeoff s

Time from the start of movement to takeoff. Indicates the total ground contact time before leaving the ground.

Time to Peak Braking Force s L / R

Time to reach peak force during braking phase, measured from braking start

Time to Peak Braking Power s L / R

Time to reach peak power during braking phase, measured from braking start

Time to Peak Propulsive Force s L / R

Time to reach peak force during propulsive phase, measured from propulsive start

Time to Peak Propulsive Power s L / R

Time to reach peak power during propulsive phase, measured from propulsive start

System Properties Basic system and timing measurements 1 metric

System weight kg

Measured weight of the user during the weighting phase, just before the jump

Jump Performance Primary outcome measures of jump performance 11 metrics

Jump Height (ft) m

Jump Height by Flight Time (FT)

\frac{g \, t_{\text{flight}}^2}{8}

$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{flight}}$: Flight time

Jump Height (ni) m

Jump Height by Net Impulse (NI)

Same as: Hawkin Dynamics: CMJ Jump Height

\frac{v_{\text{takeoff}}^2}{2g}

$v_{\text{takeoff}}$: Velocity at takeoff
$g$: Gravitational acceleration (9.81 m/s²)

Takeoff Velocity m/s

Vertical velocity of the center of mass at takeoff.

RSI (Flight Time)

Flight time divided by contact time (DJ) or by time to takeoff (CMJ/SJ).

Same as: Hawkin Dynamics: CMJ RSI

\frac{t_{\text{flight}}}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

RSI Modified

Jump height divided by contact time (DJ) or by time to takeoff (CMJ/SJ). Uses the net-impulse jump height when available.

Same as: Hawkin Dynamics: CMJ Modified RSI

Jump Momentum kg·m/s

The momentum generated during the jump, calculated as the product of body mass and takeoff velocity.

m \cdot v_{\text{takeoff}}

$m$: Body mass
$v_{\text{takeoff}}$: Velocity at takeoff

Displacement Depth m

Maximum depth of the countermovement phase, representing how far the center of mass descends before the propulsive phase begins.

Same as: Hawkin Dynamics: CMJ Depth

Reb. Jump Momentum kg·m/s

Vertical momentum at takeoff of the rebound jump (body mass × takeoff velocity).

m \cdot v_{\text{takeoff}}

$m$: Body mass
$v_{\text{takeoff}}$: Velocity at takeoff

Reb. RSI

Reactive Strength Index of rebound jump (flight time ÷ contact time).

\frac{t_{\text{flight}}}{t_{\text{contact}}}

$t_{\text{flight}}$: Flight time
$t_{\text{contact}}$: Contact time

Reb. Jump Height (ft) m

Jump height of the rebound jump, calculated from flight time.

\frac{g \, t_{\text{flight}}^2}{8}

$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{flight}}$: Flight time

Reb. RSI Modified

Modified Reactive Strength Index of the rebound jump: jump height divided by contact time.

\frac{v_{\text{takeoff}}^2}{2g \cdot t_{\text{contact}}}

$v_{\text{takeoff}}$: Velocity at takeoff
$g$: Gravitational acceleration (9.81 m/s²)
$t_{\text{contact}}$: Contact time

Impulse Metrics Impulse metrics during braking and propulsive phases 8 metrics

Net Impulse N·s L / R

The total impulse (bodyweight subtracted) applied during the braking+propulsive phase

Net Eccentric Impulse N·s L / R

Net impulse over the full eccentric phase (unweighting + braking combined). Because the athlete starts and ends this phase at rest, the two sub-phases largely cancel — values near zero are normal.

\left| \int_{\text{eccentric}} (F - BW)\,dt \right|

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Propulsive Impulse N·s L / R

Net impulse (force minus body weight) from the lowest position to takeoff. Also called concentric impulse.

Same as: Hawkin Dynamics: CMJ Propulsive Net Impulse
Not the same as: Hawkin Dynamics: CMJ Propulsive Impulse

\int_{\text{propulsive}} (F - BW)\,dt

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Rel. Propulsive Impulse N·s/kg

Net impulse during the propulsive phase relative to body mass

Same as: Hawkin Dynamics: CMJ Relative Propulsive Net Impulse
Not the same as: Hawkin Dynamics: CMJ Relative Propulsive Impulse

\frac{J_{\text{propulsive}}}{m}

$J$: Impulse
$m$: Body mass

Braking Impulse N·s L / R

Net impulse (force minus body weight) during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Net Eccentric Impulse' for the full eccentric phase.

Not the same as: Hawkin Dynamics: CMJ Braking Impulse; Hawkin Dynamics: CMJ Braking Net Impulse (see Deceleration Impulse)

Deceleration Impulse N·s

Net impulse (force minus body weight) from Eccentric Peak Velocity (EPV) to the lowest point.

Same as: Hawkin Dynamics: CMJ Braking Net Impulse

Reb. Braking Impulse N·s L / R

Total impulse generated during rebound braking phase.

Reb. Propulsive Impulse N·s L / R

Total impulse generated during rebound propulsive phase.

\int_{\text{propulsive}} (F - BW)\,dt

$F$: Vertical ground reaction force
$BW$: Body weight (m · g)

Force Metrics Force measurements during various phases and conditions 22 metrics

Peak Force N L / R

The peak instantaneous force during the entire jump

Min Unweight Force N

The minimum force measured during the unweighting phase

Rel. Min Unweight Force BW

Minimum force during the unweighting phase, as a multiple of body weight.

\frac{F_{\text{min unweighting}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Peak Braking Force N L / R

Peak force during the braking phase only, from minimum force to the lowest point (drop jump: from ground contact). See 'Peak Eccentric Force' for the full eccentric phase.

Avg Braking Force N L / R

Not the same as: Hawkin Dynamics: CMJ Avg. Braking Force (see Avg Deceleration Force)

Avg Deceleration Force N

Average force from Eccentric Peak Velocity (EPV) to the lowest point. Higher than 'Avg Braking Force' because it leaves out the early part of braking, where force is still close to body weight.

Same as: Hawkin Dynamics: CMJ Avg. Braking Force

Rel. Avg Deceleration Force N/kg

Avg Deceleration Force relative to body mass.

\frac{\bar{F}_{\text{deceleration}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Avg Eccentric Force N L / R

Average force over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Peak Eccentric Force N L / R

Peak force over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Avg Propulsive Force N L / R

The average force during the propulsive phase

Rel. Avg Propulsive Force N/kg

Average force during the propulsive phase relative to body mass

\frac{\bar{F}_{\text{propulsive}}}{m}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$m$: Body mass

Peak Propulsive Force N L / R

The peak instantaneous force during the propulsive phase

Relative Peak Force BW

Peak force output expressed as multiples of body weight

\frac{F_{\text{peak}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Force @ Peak Power N

Force at the moment of peak power.

Force @ Min Displacement N

Ground reaction force at the lowest point of the countermovement.

Rel. Force @ Min Displacement BW

Force at the lowest point of the countermovement, as a multiple of body weight.

\frac{F_{\text{min displacement}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Reb. Force @ Min Displacement N

Vertical force at the lowest point of CoM displacement during rebound contact.

Reb. Rel. Force @ Min Displacement BW

Force at min displacement during rebound, normalized to body weight.

\frac{F_{\text{min displacement}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Reb. Avg Braking Force N L / R

Average vertical force during rebound braking phase.

Reb. Peak Braking Force N L / R

Peak vertical force during rebound braking phase.

Reb. Avg Propulsive Force N L / R

Average vertical force during rebound propulsive phase.

Reb. Peak Propulsive Force N L / R

Peak vertical force during rebound propulsive phase.

Power Power output throughout the jump 17 metrics

Peak Braking Power W L / R

Peak power during the braking phase only (negative value). See 'Peak Eccentric Power' for the full eccentric phase as an absolute value.

Avg Braking Power W L / R

Average power during the braking phase only (negative value). See 'Avg Eccentric Power' for the full eccentric phase as an absolute value.

Not the same as: Hawkin Dynamics: CMJ Avg. Braking Power

Braking Work J L / R

Work done during the braking phase only (negative value). See 'Eccentric Work' for the full eccentric phase as an absolute value.

Peak Eccentric Power W L / R

Peak power over the full eccentric phase (unweighting + braking), reported as an absolute value.

Avg Eccentric Power W L / R

Average power over the full eccentric phase (unweighting + braking), reported as an absolute value.

Eccentric Work J L / R

Work done over the full eccentric phase (unweighting + braking), reported as an absolute value.

\left| \overline{F \cdot v} \cdot \Delta t_{\text{eccentric}} \right|

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Propulsive Power W L / R

The maximum power output during the propulsive phase

Avg Propulsive Power W L / R

The average power output during the propulsive phase

Propulsive Work J L / R

The total work done during the propulsive phase

\overline{F \cdot v} \cdot \Delta t_{\text{propulsive}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Peak Power W

The peak instantaneous power during the entire jump

Relative Peak Power W/kg

Peak power output expressed as watts per kilogram of body weight

Same as: Hawkin Dynamics: CMJ Peak Relative Propulsive Power

\frac{P_{\text{peak}}}{m}

$P$: Power (F · v)
$m$: Body mass

Reb. Avg Braking Power W L / R

Average power during rebound braking phase.

Reb. Peak Braking Power W L / R

Peak power during rebound braking phase.

Reb. Avg Propulsive Power W L / R

Average power during rebound propulsive phase.

Reb. Peak Propulsive Power W L / R

Peak power during rebound propulsive phase.

Reb. Braking Work J L / R

The total work done during the rebound braking phase.

Reb. Propulsive Work J L / R

The total work done during the rebound propulsive phase.

\overline{F \cdot v} \cdot \Delta t_{\text{propulsive}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass
$\Delta t$: Duration of the phase named in the subscript

Velocity Velocity throughout the jump 12 metrics

Min Braking Velocity m/s

The minimum velocity during the braking phase

Avg Braking Velocity m/s

The average velocity during the braking phase

Min Eccentric Velocity m/s

Fastest downward velocity (most negative value) in the eccentric phase, also called Eccentric Peak Velocity (EPV). It marks the start of the deceleration phase.

Avg Eccentric Velocity m/s

Average velocity over the full eccentric phase (unweighting + braking), from movement start to the lowest point.

Peak Propulsive Velocity m/s

The highest velocity reached during the propulsive phase

Avg Propulsive Velocity m/s

The average velocity during the propulsive phase

Peak Velocity m/s

The peak instantaneous velocity during the propulsion phase

Velocity @ Peak Power m/s

Velocity at the moment of peak power.

Reb. Min Braking Velocity m/s

The minimum velocity during the rebound braking phase.

Reb. Avg Braking Velocity m/s

The average velocity during the rebound braking phase.

Reb. Peak Propulsive Velocity m/s

The highest velocity reached during the rebound propulsive phase.

Reb. Avg Propulsive Velocity m/s

The average velocity during the rebound propulsive phase.

Force Development Rate of force development and force application speed 7 metrics

Avg RFD N/s L / R

Average rate of force development: the rise in force up to peak force, divided by the time to peak force.

Avg Braking RFD N/s L / R

The average slope of force during the braking phase

Not the same as: Hawkin Dynamics: CMJ Braking RFD (see Deceleration RFD)

Deceleration RFD N/s L / R

Rate of force development in the deceleration phase, from Eccentric Peak Velocity (EPV) to the lowest point. Similar to 'Braking RFD' or 'Load' in other systems.

Same as: Hawkin Dynamics: CMJ Braking RFD

\frac{F_{\text{braking end}} - F_{v_{\min}}}{t_{\text{braking end}} - t_{v_{\min}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript
$v_{\min}$: Lowest (most downward) velocity, where deceleration starts

Eccentric RFD N/s L / R

Rate of force development during the eccentric phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Propulsive RFD N/s L / R

Rate of force development during the propulsive phase, calculated from initial to peak force

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Reb. Avg Braking RFD N/s L / R

The average slope of force during the rebound braking phase.

Reb. Propulsive RFD N/s L / R

Rate of force development during the rebound propulsive phase, calculated from initial to peak force.

\frac{F_{\text{peak}} - F_{\text{start}}}{t_{F_{\text{peak}}} - t_{\text{start}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

P1/P2 Analysis Analysis of early vs late propulsive phase characteristics 40 metrics

P1 Impulse N·s L / R

P2 Impulse N·s L / R

Impulse generated during the second half of the propulsive phase (to triple-extension position). Represents the final 50% of propulsive impulse, typically when the athlete is extending to takeoff.

P1 Duration s

Time duration of the first half of the propulsive phase. Indicates how quickly the athlete generates the first 50% of propulsive impulse from the triple-flexed position.

P2 Duration s

Time duration of the second half of the propulsive phase. Indicates how quickly the athlete generates the final 50% of propulsive impulse moving into triple-extension.

P1 Avg Force N

Average force during the first half of the propulsive phase. Indicates force production capability in the deep squat position.

P2 Avg Force N

Average force during the second half of the propulsive phase. Indicates force production capability in the extension to takeoff.

P1:P2 Force Ratio

\frac{\bar{F}_{P1}}{\bar{F}_{P2}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1:P2 Duration Ratio

\frac{t_{P1}}{t_{P2}}

$t$: Time of the event named in the subscript
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1 Peak Force N

Peak force during early propulsive phase (P1)

P1 Peak Velocity m/s

Peak velocity during early propulsive phase (P1)

P1 Avg Velocity m/s

Average velocity during early propulsive phase (P1)

P1 Peak Power W

Peak power during early propulsive phase (P1)

P1 Avg Power W

Average power during early propulsive phase (P1)

P2 Peak Force N

Peak force during late propulsive phase (P2)

P2 Peak Velocity m/s

Peak velocity during late propulsive phase (P2)

P2 Avg Velocity m/s

Average velocity during late propulsive phase (P2)

P2 Peak Power W

Peak power during late propulsive phase (P2)

P2 Avg Power W

Average power during late propulsive phase (P2)

P1/P2 Velocity Ratio

Ratio of P1 to P2 average velocity, indicating early vs late phase velocity characteristics

\frac{\bar{v}_{P1}}{\bar{v}_{P2}}

$\bar{x}$: Mean value
$v$: Vertical velocity of the center of mass
$P1,\ P2$: First and second half of the propulsive phase (split by time)

P1/P2 Power Ratio

Ratio of P1 to P2 average power, indicating early vs late phase power characteristics

\frac{\bar{P}_{P1}}{\bar{P}_{P2}}

$\bar{x}$: Mean value
$P$: Power (F · v)
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Reb. P1 Impulse N·s L / R

Impulse during first half of rebound propulsive phase (split at 50% of total propulsive impulse).

Reb. P2 Impulse N·s L / R

Impulse during second half of rebound propulsive phase (split at 50% of total propulsive impulse).

Reb. P1 Duration s

Time duration of the first half of the rebound propulsive phase.

Reb. P1 Peak Force N

Peak force during early rebound propulsive phase (P1).

Reb. P1 Avg Force N

Average force during the first half of the rebound propulsive phase.

Reb. P1 Peak Velocity m/s

Peak velocity during early rebound propulsive phase (P1).

Reb. P1 Avg Velocity m/s

Average velocity during early rebound propulsive phase (P1).

Reb. P1 Peak Power W

Peak power during early rebound propulsive phase (P1).

Reb. P1 Avg Power W

Average power during early rebound propulsive phase (P1).

Reb. P2 Duration s

Time duration of the second half of the rebound propulsive phase.

Reb. P2 Peak Force N

Peak force during late rebound propulsive phase (P2).

Reb. P2 Avg Force N

Average force during the second half of the rebound propulsive phase.

Reb. P2 Peak Velocity m/s

Peak velocity during late rebound propulsive phase (P2).

Reb. P2 Avg Velocity m/s

Average velocity during late rebound propulsive phase (P2).

Reb. P2 Peak Power W

Peak power during late rebound propulsive phase (P2).

Reb. P2 Avg Power W

Average power during late rebound propulsive phase (P2).

Reb. P1:P2 Force Ratio

Ratio of average force in rebound P1 to rebound P2.

\frac{\bar{F}_{P1}}{\bar{F}_{P2}}

$\bar{x}$: Mean value
$F$: Vertical ground reaction force
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Reb. P1/P2 Velocity Ratio

Ratio of rebound P1 to P2 average velocity, indicating early vs late phase velocity characteristics.

\frac{\bar{v}_{P1}}{\bar{v}_{P2}}

$\bar{x}$: Mean value
$v$: Vertical velocity of the center of mass
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Reb. P1/P2 Power Ratio

Ratio of rebound P1 to P2 average power, indicating early vs late phase power characteristics.

\frac{\bar{P}_{P1}}{\bar{P}_{P2}}

$\bar{x}$: Mean value
$P$: Power (F · v)
$P1,\ P2$: First and second half of the propulsive phase (split by time)

Reb. P1:P2 Duration Ratio

Ratio of rebound P1 duration to rebound P2 duration.

Landing Metrics Force absorption and landing mechanics measurements. For Drop Jumps, these reflect the final landing after the rebound jump — not the initial drop off the box. 8 metrics

Peak Landing Force N L / R

The maximum force recorded during the landing phase of the jump. Measures the ability to absorb force upon landing.

Rel. Peak Landing Force BW

Peak landing force as a multiple of body weight.

\frac{F_{\text{peak landing}}}{m \, g}

$F$: Vertical ground reaction force
$m$: Body mass
$g$: Gravitational acceleration (9.81 m/s²)

Time to Peak Landing Force s L / R

Time from landing contact to peak landing force. Indicates how quickly peak forces are reached during landing.

Avg Landing RFD N/s L / R

Average rate of force development during landing, calculated from bodyweight to peak landing force over time. Indicates landing stiffness.

Landing RFD 0-20ms N/s L / R

Rate of force development during the first 20ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 20\,\text{ms}) - F(t_{\text{landing}})}{20\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-40ms N/s L / R

Rate of force development during the first 40ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 40\,\text{ms}) - F(t_{\text{landing}})}{40\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-60ms N/s L / R

Rate of force development during the first 60ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 60\,\text{ms}) - F(t_{\text{landing}})}{60\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Landing RFD 0-80ms N/s L / R

Rate of force development during the first 80ms after landing (post-jump). For DJ, this is the final landing, not the initial drop contact.

\frac{F(t_{\text{landing}} + 80\,\text{ms}) - F(t_{\text{landing}})}{80\,\text{ms}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Timing Timing related metrics 22 metrics

Time to Peak Force s L / R

Time from the start of the jump to peak force. For SJ it is measured from the start of the propulsive phase, for DJ from ground contact.

Unweighting Duration s

Time from the start of movement to minimum force.

Braking Duration s

Time from minimum force to the lowest point of the countermovement. Shorter than the full eccentric phase, which also includes unweighting.

Deceleration Duration s

Time from Eccentric Peak Velocity (EPV) to the lowest point of the countermovement. This is the later part of the braking phase.

t_{\text{braking end}} - t_{v_{\min}}

$t$: Time of the event named in the subscript
$v_{\min}$: Lowest (most downward) velocity, where deceleration starts

Propulsive Duration s

Time from the end of the braking phase (when velocity turns positive) to takeoff. Also called concentric time.

Flight Time s

Time spent in the flight phase

Time to Peak Power s L / R

The time from the start of the jump to the moment of peak power output

Contraction Time s

Time from movement start to takeoff. For CMJ this covers the eccentric and concentric phases, for SJ only the propulsive phase, and for DJ the time from landing to takeoff.

Same as: Hawkin Dynamics: CMJ Time To Takeoff

Time to Takeoff s

Time from the start of movement to takeoff. Indicates the total ground contact time before leaving the ground.

Time to Peak Braking Force s L / R

Time to reach peak force during braking phase, measured from braking start

Time to Peak Braking Power s L / R

Time to reach peak power during braking phase, measured from braking start

Time to Peak Eccentric Force s L / R

Time to reach peak force during eccentric phase, measured from jump start

Time to Peak Eccentric Power s L / R

Time to reach peak power during eccentric phase, measured from jump start

Time to Peak Propulsive Force s L / R

Time to reach peak force during propulsive phase, measured from propulsive start

Time to Peak Propulsive Power s L / R

Time to reach peak power during propulsive phase, measured from propulsive start

Reb. Flight Time s

Airborne duration of the rebound jump.

Reb. Time to Peak Braking Force s L / R

Time from start of rebound contact to peak braking force.

Reb. Time to Takeoff s

Time from start of rebound contact to rebound takeoff.

Reb. Contact Time s

Ground contact duration between landing from CMJ and takeoff of the rebound jump.

Reb. Time to Peak Braking Power s L / R

Time to reach peak power during rebound braking phase, measured from braking start.

Reb. Time to Peak Propulsive Force s L / R

Time to reach peak force during rebound propulsive phase, measured from propulsive start.

Reb. Time to Peak Propulsive Power s L / R

Time to reach peak power during rebound propulsive phase, measured from propulsive start.

System Properties Basic system and timing measurements 1 metric

System weight kg

Measured weight of the user during the weighting phase, just before the jump

Force Force measurement metrics during muscle contractions 10 metrics

Force @ Onset N

Force at the onset of the contraction

Peak Force @ Rise end N

Force at the end of the rising phase, where the rate of force development settles to its steady-state level.

Peak Force N L / R

Highest force during the maximal voluntary contraction.

Force @ 50ms N L / R

Force at 50ms from onset

Force @ 100ms N L / R

Force at 100ms from onset

Force @ 150ms N L / R

Force at 150ms from onset

Force @ 200ms N L / R

Force at 200ms from onset

Force @ 250ms N L / R

Force at 250ms from onset

Force @ Peak RFD N L / R

Force at the point where maximum RFD is reached

Bodyweight N

Bodyweight measured on the force platform

Rate of Force Development Metrics measuring how quickly force is developed during contractions 6 metrics

Peak RFD N/s L / R

Peak Rate of Force Development during contraction

\max_i \, (F_i - F_{i-1}) \cdot f_s

$F$: Vertical ground reaction force
$f_s$: Sampling rate

RFD @ 50ms N/s L / R

Rate of Force Development at 50ms from onset

\frac{F(t_{\text{onset}} + 50\,\text{ms}) - F(t_{\text{onset}})}{50\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 100ms N/s L / R

Rate of Force Development at 100ms from onset

\frac{F(t_{\text{onset}} + 100\,\text{ms}) - F(t_{\text{onset}})}{100\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 150ms N/s L / R

Rate of Force Development at 150ms from onset

\frac{F(t_{\text{onset}} + 150\,\text{ms}) - F(t_{\text{onset}})}{150\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 200ms N/s L / R

Rate of Force Development at 200ms from onset

\frac{F(t_{\text{onset}} + 200\,\text{ms}) - F(t_{\text{onset}})}{200\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 250ms N/s L / R

Rate of Force Development at 250ms from onset

\frac{F(t_{\text{onset}} + 250\,\text{ms}) - F(t_{\text{onset}})}{250\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse Impulse metrics measuring force integrated over time periods 7 metrics

Impulse @ 50ms N·s

Impulse from onset to 50ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 50\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 100ms N·s

Impulse from onset to 100ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 100\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 150ms N·s

Impulse from onset to 150ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 150\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 200ms N·s

Impulse from onset to 200ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 200\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 250ms N·s

Impulse from onset to 250ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 250\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse to RFD Max N·s

Impulse from onset to maximum RFD

\int\limits_{t_{\text{onset}}}^{t_{RFD_{\max}}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction
$t$: Time of the event named in the subscript

Impulse to Peak Force N·s

Impulse from onset to peak force

Steadiness Metrics measuring the stability and consistency of force output 2 metrics

Force Steadiness N

Root mean square error of force during steady state

RFD Steadiness N/s

Root mean square error of RFD during steady state

Timing Timing related metrics 4 metrics

Time to Peak RFD s

Time from onset to maximum RFD

Time to End Of Rise s

Time from onset to End Of Rise during contraction

Time of Onset s

Time of onset of the contraction (from the beginning of the signal)

Time to Peak Force s

Time from onset to peak force during maximum voluntary contraction

Torque Torque metrics calculated by multiplying force by limb length 9 metrics

Torque @ Onset Nm

Torque at the onset of the contraction

Peak Torque @ Rise end Nm

Torque at the end of the rising phase, where the rate of torque development settles to its steady-state level.

Peak Torque Nm L / R

Highest torque during the maximal voluntary contraction.

Torque @ 50ms Nm L / R

Torque at 50ms from onset

Torque @ 100ms Nm L / R

Torque at 100ms from onset

Torque @ 150ms Nm L / R

Torque at 150ms from onset

Torque @ 200ms Nm L / R

Torque at 200ms from onset

Torque @ 250ms Nm L / R

Torque at 250ms from onset

Torque @ Peak RFD Nm L / R

Torque at the point where maximum RFD is reached

Net Force Force measurement metrics during muscle contractions (bodyweight subtracted) 9 metrics

Net Force @ Onset N

(Net) Force at the onset of the contraction

Net Peak Force @ Rise end N

(Net) Force at the end of the rising phase, where the rate of force development settles to its steady-state level.

Net Peak Force N L / R

(Net) Highest force during the maximal voluntary contraction.

Net Force @ 50ms N L / R

(Net) Force at 50ms from onset

Net Force @ 100ms N L / R

(Net) Force at 100ms from onset

Net Force @ 150ms N L / R

(Net) Force at 150ms from onset

Net Force @ 200ms N L / R

(Net) Force at 200ms from onset

Net Force @ 250ms N L / R

(Net) Force at 250ms from onset

Net Force @ Peak RFD N L / R

(Net) Force at the point where maximum RFD is reached

Relative Force Force measurement metrics during muscle contractions (normalized to bodyweight) 9 metrics

Rel. Force @ Onset %

Force at the onset of the contraction as a percentage of body weight

Rel. Peak Force @ Rise end %

Force at the end of the rising phase, where the rate of force development settles to its steady-state level. as a percentage of body weight

Rel. Peak Force % L / R

Highest force during the maximal voluntary contraction. as a percentage of body weight

Rel. Force @ 50ms % L / R

Force at 50ms from onset as a percentage of body weight

Rel. Force @ 100ms % L / R

Force at 100ms from onset as a percentage of body weight

Rel. Force @ 150ms % L / R

Force at 150ms from onset as a percentage of body weight

Rel. Force @ 200ms % L / R

Force at 200ms from onset as a percentage of body weight

Rel. Force @ 250ms % L / R

Force at 250ms from onset as a percentage of body weight

Rel. Force @ Peak RFD % L / R

Force at the point where maximum RFD is reached as a percentage of body weight

Relative Net Force Force measurement metrics during muscle contractions (bodyweight subtracted, normalized to bodyweight) 9 metrics

Rel. Net Force @ Onset %

(Net) Force at the onset of the contraction as a percentage of body weight

Rel. Net Peak Force @ Rise end %

(Net) Force at the end of the rising phase, where the rate of force development settles to its steady-state level. as a percentage of body weight

Rel. Net Peak Force % L / R

(Net) Highest force during the maximal voluntary contraction. as a percentage of body weight

Rel. Net Force @ 50ms % L / R

(Net) Force at 50ms from onset as a percentage of body weight

Rel. Net Force @ 100ms % L / R

(Net) Force at 100ms from onset as a percentage of body weight

Rel. Net Force @ 150ms % L / R

(Net) Force at 150ms from onset as a percentage of body weight

Rel. Net Force @ 200ms % L / R

(Net) Force at 200ms from onset as a percentage of body weight

Rel. Net Force @ 250ms % L / R

(Net) Force at 250ms from onset as a percentage of body weight

Rel. Net Force @ Peak RFD % L / R

(Net) Force at the point where maximum RFD is reached as a percentage of body weight

Net Impulse Impulse metrics measuring force integrated over time periods (bodyweight subtracted) 7 metrics

Net Impulse @ 50ms N·s

(Net) Impulse from onset to 50ms

Net Impulse @ 100ms N·s

(Net) Impulse from onset to 100ms

Net Impulse @ 150ms N·s

(Net) Impulse from onset to 150ms

Net Impulse @ 200ms N·s

(Net) Impulse from onset to 200ms

Net Impulse @ 250ms N·s

(Net) Impulse from onset to 250ms

Net Impulse to RFD Max N·s

(Net) Impulse from onset to maximum RFD

Net Impulse to Peak Force N·s

(Net) Impulse from onset to peak force

Relative Impulse Impulse metrics measuring force integrated over time periods (normalized to bodyweight) 7 metrics

Rel. Impulse @ 50ms %

Impulse from onset to 50ms as a percentage of body weight

Rel. Impulse @ 100ms %

Impulse from onset to 100ms as a percentage of body weight

Rel. Impulse @ 150ms %

Impulse from onset to 150ms as a percentage of body weight

Rel. Impulse @ 200ms %

Impulse from onset to 200ms as a percentage of body weight

Rel. Impulse @ 250ms %

Impulse from onset to 250ms as a percentage of body weight

Rel. Impulse to RFD Max %

Impulse from onset to maximum RFD as a percentage of body weight

Rel. Impulse to Peak Force %

Impulse from onset to peak force as a percentage of body weight

Relative Net Impulse Impulse metrics measuring force integrated over time periods (bodyweight subtracted, normalized to bodyweight) 7 metrics

Rel. Net Impulse @ 50ms %

(Net) Impulse from onset to 50ms as a percentage of body weight

Rel. Net Impulse @ 100ms %

(Net) Impulse from onset to 100ms as a percentage of body weight

Rel. Net Impulse @ 150ms %

(Net) Impulse from onset to 150ms as a percentage of body weight

Rel. Net Impulse @ 200ms %

(Net) Impulse from onset to 200ms as a percentage of body weight

Rel. Net Impulse @ 250ms %

(Net) Impulse from onset to 250ms as a percentage of body weight

Rel. Net Impulse to RFD Max %

(Net) Impulse from onset to maximum RFD as a percentage of body weight

Rel. Net Impulse to Peak Force %

(Net) Impulse from onset to peak force as a percentage of body weight

Force Force measurements throughout movement phases 7 metrics

Peak Force N L / R

Highest total force at any point during the rep

Eccentric Peak Force N L / R

Maximum force during the lowering/eccentric phase

Concentric Peak Force N L / R

Maximum force during the upward/concentric phase

Mean Force N

Average force over the whole rep (descent, pause and ascent)

Mean Eccentric Force N

Average force during the eccentric phase

Mean Concentric Force N

Average force during the concentric phase

Starting Force N

Force at the start of the rep, standing still (approximately body weight + external load)

Velocity Speed and velocity metrics during movement 5 metrics

Peak Velocity m/s

Highest speed reached in either direction (downward or upward)

Eccentric Peak Velocity m/s

Maximum downward velocity (negative value)

Concentric Peak Velocity m/s

Maximum upward velocity

Mean Eccentric Velocity m/s

Average velocity during eccentric phase

Mean Concentric Velocity m/s

Average velocity during concentric phase

Displacement Movement distance and position metrics 3 metrics

Maximum Displacement m

Largest distance of the center of mass from its height at rep start (usually equals squat depth)

Maximum Negative Displacement m

Squat depth: lowest point below the height at rep start (negative value)

Total Displacement m

Total vertical distance traveled during the rep (down plus up, roughly twice the depth)

\sum_i |\Delta s_i|

$\Delta s_i$: Change in center of mass position between samples

Power Power output metrics (force × velocity) 4 metrics

Peak Power W L / R

Highest power output (force × velocity) during the rep, reached during the ascent

Concentric Peak Power W

Maximum power during concentric phase

Mean Eccentric Power W

Average power during eccentric phase

Mean Concentric Power W

Average power during concentric phase

Timing Time-based metrics and phase durations 8 metrics

Total Movement Time s

Duration of the whole rep, from the start of the descent until standing back up

Eccentric Duration s

Time spent in eccentric/lowering phase

Amortization Phase s

Time at the bottom between lowering and rising

Concentric Duration s

Time spent in concentric/upward phase

Time to Peak Force s

Time from the start of the rep to maximum force

Time to Peak Power s

Time from the start of the rep to maximum power

Time to Peak Velocity s

Time from the start of the rep to maximum speed

Contraction Time s

Combined duration of the lowering and rising phases (excludes the initial dip and the pause at the bottom)

t_{\text{eccentric}} + t_{\text{concentric}}

$t$: Time of the event named in the subscript

Impulse Force integrated over time (area under curve) 4 metrics

Total Impulse N·s L / R

Net impulse over the whole rep: force above or below the standing weight (body weight + load), integrated over time

\int_{\text{rep}} (F - W_{\text{system}})\,dt

$F$: Vertical ground reaction force
$W_{\text{system}}$: System weight: body weight plus external load

Eccentric Impulse N·s

Net impulse during the lowering phase, relative to the standing weight

\int_{\text{eccentric}} (F - W_{\text{system}})\,dt

$F$: Vertical ground reaction force
$W_{\text{system}}$: System weight: body weight plus external load

Concentric Impulse N·s

Net impulse during the ascent, relative to the standing weight

\int_{\text{concentric}} (F - W_{\text{system}})\,dt

$F$: Vertical ground reaction force
$W_{\text{system}}$: System weight: body weight plus external load

Net Impulse N·s

Concentric impulse minus the magnitude of the eccentric impulse

J_{\text{concentric}} - |J_{\text{eccentric}}|

$J$: Impulse

Performance Overall performance indicators 3 metrics

Eccentric Work J

Work performed during the lowering phase (negative value)

\int_{\text{eccentric}} F \cdot v\,dt

$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass

Concentric Work J

Work performed during concentric phase

\int_{\text{concentric}} F \cdot v\,dt

$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass

Force-Velocity Ratio N·s/m

Peak force divided by peak speed in the rep

\frac{F_{\text{peak}}}{|v|_{\text{peak}}}

$F$: Vertical ground reaction force
$v$: Vertical velocity of the center of mass

Bilateral Symmetry Left-right symmetry indices across different metrics 1 metric

Weight Distribution % L / R

Share of the total load carried by the left leg, averaged over the whole rep. 50% is balanced.

\frac{\bar{F}_{\text{left}}}{\bar{F}_{\text{total}}} \times 100

$\bar{x}$: Mean value
$F$: Vertical ground reaction force

Load External load and relative strength metrics 4 metrics

External Load kg

External load entered for the set (barbell, vest). Entered manually, not measured by the plates.

Total System Weight N

Body weight plus external load, in newtons: the force on the plates during quiet standing

(m_{\text{body}} + m_{\text{load}}) \, g

$m_{\text{body}}$: Body mass
$m_{\text{load}}$: External load
$g$: Gravitational acceleration (9.81 m/s²)

Relative Peak Force N/kg

Peak force per kilogram of body mass. External load is not included in the divisor.

\frac{F_{\text{peak}}}{m_{\text{body}}}

$F$: Vertical ground reaction force
$m_{\text{body}}$: Body mass

Relative Peak Power W/kg

Peak power per kilogram of body mass. External load is not included in the divisor.

\frac{P_{\text{peak}}}{m_{\text{body}}}

$P$: Power (F · v)
$m_{\text{body}}$: Body mass

Weight Shift 3 metrics

Backswing Weight % L / R

Percentage of weight on left plate at peak backswing

Impact Weight % L / R

Percentage of weight on left plate at impact

Peak Weight Shift %

Maximum change in weight distribution from backswing to impact

Timing 5 metrics

Transition Time s

Time from peak backswing to weight reversal

Backswing Duration s

Time from swing start to peak backswing

Downswing Duration s

Time from peak backswing to impact

Total Swing Time s

Total time from swing start to impact

Tempo Ratio

Backswing duration divided by downswing duration (ideal ~3:1)

\frac{t_{\text{backswing}}}{t_{\text{downswing}}}

$t$: Time of the event named in the subscript

Force 6 metrics

Peak Impact Force N

Maximum vertical ground reaction force at impact

Average Swing Force N

Average vertical ground reaction force during swing

Force Rate of Development N/s

Rate of force application during downswing

\frac{F_{\text{impact}} - F_{\text{backswing}}}{t_{\text{downswing}}}

$F$: Vertical ground reaction force
$t$: Time of the event named in the subscript

Peak RTD N·m/s

Peak Rate of Torque development during downswing transition

RTD @ 100ms N·m/s

Rate of Torque development at 100ms from transition

RTD @ 200ms N·m/s

Rate of Torque development at 200ms from transition

CoP Position 6 metrics

CoP Backswing X mm

Center of pressure lateral position at peak backswing

CoP Backswing Y mm

Center of pressure anterior-posterior position at peak backswing

CoP Transition X mm

Center of pressure lateral position at transition

CoP Transition Y mm

Center of pressure anterior-posterior position at transition

CoP Impact X mm

Center of pressure lateral position at impact

CoP Impact Y mm

Center of pressure anterior-posterior position at impact

CoP Movement 6 metrics

CoP Path Length mm

Total distance traveled by center of pressure during swing

CoP Sway Area mm²

95% confidence ellipse area encompassing CoP movement (indicates stability)

CoP Peak Velocity mm/s

Maximum velocity of center of pressure during transition phase

CoP Lateral Sway Range mm

Total lateral (side-to-side) range of center of pressure movement

CoP A-P Sway Range mm

Total anterior-posterior (front-back) range of center of pressure movement

CoP Shift Magnitude mm

Total distance of center of pressure shift from backswing to impact

Force Force measurement metrics during muscle contractions 10 metrics

Force @ Onset N

Force at the onset of the contraction

Peak Force @ Rise end N

Force at the end of the rising phase, where the rate of force development settles to its steady-state level.

Peak Force N L / R

Highest force during the maximal voluntary contraction.

Force @ 50ms N L / R

Force at 50ms from onset

Force @ 100ms N L / R

Force at 100ms from onset

Force @ 150ms N L / R

Force at 150ms from onset

Force @ 200ms N L / R

Force at 200ms from onset

Force @ 250ms N L / R

Force at 250ms from onset

Force @ Peak RFD N L / R

Force at the point where maximum RFD is reached

Bodyweight N

Bodyweight measured on the force platform

Rate of Force Development Metrics measuring how quickly force is developed during contractions 6 metrics

Peak RFD N/s L / R

Peak Rate of Force Development during contraction

\max_i \, (F_i - F_{i-1}) \cdot f_s

$F$: Vertical ground reaction force
$f_s$: Sampling rate

RFD @ 50ms N/s L / R

Rate of Force Development at 50ms from onset

\frac{F(t_{\text{onset}} + 50\,\text{ms}) - F(t_{\text{onset}})}{50\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 100ms N/s L / R

Rate of Force Development at 100ms from onset

\frac{F(t_{\text{onset}} + 100\,\text{ms}) - F(t_{\text{onset}})}{100\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 150ms N/s L / R

Rate of Force Development at 150ms from onset

\frac{F(t_{\text{onset}} + 150\,\text{ms}) - F(t_{\text{onset}})}{150\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 200ms N/s L / R

Rate of Force Development at 200ms from onset

\frac{F(t_{\text{onset}} + 200\,\text{ms}) - F(t_{\text{onset}})}{200\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

RFD @ 250ms N/s L / R

Rate of Force Development at 250ms from onset

\frac{F(t_{\text{onset}} + 250\,\text{ms}) - F(t_{\text{onset}})}{250\,\text{ms}}

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse Impulse metrics measuring force integrated over time periods 7 metrics

Impulse @ 50ms N·s

Impulse from onset to 50ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 50\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 100ms N·s

Impulse from onset to 100ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 100\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 150ms N·s

Impulse from onset to 150ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 150\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 200ms N·s

Impulse from onset to 200ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 200\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse @ 250ms N·s

Impulse from onset to 250ms

\int\limits_{t_{\text{onset}}}^{t_{\text{onset}} + 250\,\text{ms}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction

Impulse to RFD Max N·s

Impulse from onset to maximum RFD

\int\limits_{t_{\text{onset}}}^{t_{RFD_{\max}}} F\,dt

$F$: Vertical ground reaction force
$t_{\text{onset}}$: Onset of the contraction
$t$: Time of the event named in the subscript

Impulse to Peak Force N·s

Impulse from onset to peak force

Steadiness Metrics measuring the stability and consistency of force output 2 metrics

Force Steadiness N

Root mean square error of force during steady state

RFD Steadiness N/s

Root mean square error of RFD during steady state

Timing Timing related metrics 4 metrics

Time to Peak RFD s

Time from onset to maximum RFD

Time to End Of Rise s

Time from onset to End Of Rise during contraction

Time of Onset s

Time of onset of the contraction (from the beginning of the signal)

Time to Peak Force s

Time from onset to peak force during maximum voluntary contraction

Torque Torque metrics calculated by multiplying force by limb length 9 metrics

Torque @ Onset Nm

Torque at the onset of the contraction

Peak Torque @ Rise end Nm

Torque at the end of the rising phase, where the rate of torque development settles to its steady-state level.

Peak Torque Nm L / R

Highest torque during the maximal voluntary contraction.

Torque @ 50ms Nm L / R

Torque at 50ms from onset

Torque @ 100ms Nm L / R

Torque at 100ms from onset

Torque @ 150ms Nm L / R

Torque at 150ms from onset

Torque @ 200ms Nm L / R

Torque at 200ms from onset

Torque @ 250ms Nm L / R

Torque at 250ms from onset

Torque @ Peak RFD Nm L / R

Torque at the point where maximum RFD is reached

Go deeper on the metrics

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