Table 1.
SLDJ variables description and calculation method.
| Variables | Unit | Variables description/Calculation method |
|---|---|---|
| CT | s | Ground contact end time—ground contact start time |
| Ground contact start time | s | vGRF > 10 N |
| Ground contact end time | s | vGRF < 10 N |
| FT | s | Flight end time—flight start time |
| Flight start time | s | vGRF < 10 N |
| Flight end time | s | vGRF > 10 N |
| JH | m | JH = FT2 × 9.81/8 |
| RSI | m/s | Jump height/contact time |
| Mean braking force | N | The average force produced in the braking phase |
| Peak braking force | N | The maximum force produced in the braking phase |
| Braking phase | s | One sample after the instant of peak negative COM velocity and continues through to zero COM velocity |
| Mean propulsion force | N | The average force produced in the propulsion phase |
| Peak propulsion force | N | The maximum force produced in the propulsion phase |
| Propulsion phase | s | This phase begins when a positive COM velocity is achieved (one sample after zero) until take-off (a force threshold equal to 5 times the standard deviation of flight force when the force platform is unloaded) |
COM = center of mass, CT = contact time, FT = flight time, JH = jump height, RSI = reactive strength index, SLDJ = single leg drop jump.