Table 1.
Selected force–time variable calculations.
| Variables | Calculation | CMJ? | DJ? |
|---|---|---|---|
| RSI (AU) | Jump Height divided by Ground Contact Time. | X | |
| mRSI (AU) | Jump Height divided by Time to Takeoff. | X | |
| Jump Height (m) | The change in centre of mass position between the instant of take-off and peak positive vertical displacement of the centre of mass during the flight phase, calculated as takeoff velocity squared divided by 19.62. | X | X |
| Flight Time (s) | The time taken to complete the flight phase. | X | X |
|
Ground Contact
Time (s) |
The total time taken from instant of touchdown the instant of take-off. |
X | |
|
Time to
Takeoff (s) |
The total time taken from the onset of movement to the instant of take-off. |
X | |
|
Mean Propulsive
Power (W) |
The mean mechanical power applied to the centre of mass during the propulsive phase. | X | X |
|
Peak Propulsive
Power (W) |
The peak instantaneous mechanical power applied to the centre of mass during the propulsive phase. | X | X |
|
Peak Propulsive
Velocity (m/s) |
The peak instantaneous vertical velocity of the centre of mass during the propulsive phase. | X | X |
|
Net Propulsive
Impulse (N.s) |
The net vertical impulse applied to the centre of mass during the propulsive phase. | X | X |
|
Mean Propulsive
Force (N) |
The mean vertical ground reaction force applied to the centre of mass during the propulsive phase. | X | X |
|
Peak Propulsive
Force (N) |
The peak instantaneous vertical ground reaction force applied to the centre of mass during the propulsive phase. | X | X |
| Stiffness (N/m) | Peak braking force divided by braking depth. | X | |
| Braking Depth (m) | The peak negative vertical displacement of the centre of mass during the braking phase. | X | |
|
Countermovement
Depth (m) |
The peak negative vertical displacement of the centre of mass during the braking phase. | X | |
|
Mean Braking
Power (W) |
The mean mechanical power applied to the centre of mass during the braking phase. | X | X |
|
Peak Braking
Power (W) |
The peak negative instantaneous mechanical power applied to the centre of mass during the braking phase. | X | X |
|
Net Braking
Impulse (N.s) |
The net vertical impulse applied to the centre of mass during the braking phase. | X | X |
|
Mean Braking
Force (N) |
The mean vertical ground reaction force applied to the centre of mass during the braking phase. | X | X |
|
Peak Braking
Force (N) |
The peak instantaneous vertical ground reaction force applied to the centre of mass during the braking phase. | X | X |
Key: RSI, reactive strength index; mRSI, modified reactive strength index; AU, arbitrary unit; m, metres; s, seconds; W, watts; N, Newtons; CMJ, countermovement jump; DJ, drop jump; X, included.