Table 1.
Determination of each phase and metric during the countermovement jump.
| Phases | Description |
|---|---|
| Eccentric | Negative velocity starting from point where a 20 N threshold is exceeded until velocity = 0 m·s−1 |
| Braking | Eccentric subphase: point of minimum force until velocity = 0 m·s−1 |
| Deceleration | Eccentric subphase: peak negative velocity to 0 m·s−1 |
| Concentric | Positive velocity from = m·s−1 until takeoff |
| Flight | From when vGRF falls below 30 N until vGRF return to above 30 N |
| Variables | Description |
| Jump height (cm) | Maximal jump height computed using impulse-momentum method |
| RSImod (m/sec) | Jump height (calculated from flight time) divided by contraction time |
| Braking duration—Contraction Time | Duration of the braking phase divided by contraction time |
| COM Displacement (cm) | Maximal vertical center of mass displacement during initial ground contact |
| Deceleration duration (ms) | Time period from maximum negative velocity to zero velocity at the end of the eccentric phase |
| Eccentric Duration (ms) | Duration of the eccentric phase |
| Eccentric Peak Force ABS (N) | Greatest force achieved during the eccentric phase |
| Eccentric Peak Force REL (N) | Greatest force achieved during the eccentric phase relative to the athletés weight |
| Eccentric Peak Power ABS (W) | Greatest power achieved during the eccentric phase |
| Eccentric Peak Power REL (W) | Greatest power achieved during the eccentric phase relative to the athletés weight |
| Eccentric Peak Velocity (m/s) | Greatest velocity achieved during the eccentric phase |
| Concentric Duration (ms) | Duration of the concentric phase |
| Concentric Peak Force ABS (N) | Greatest force achieved during the concentric phase |
| Concentric Peak Force REL (N) | Greatest force achieved during the concentric phase relative to the athletés weight |
| Concentric Peak Power ABS (W) | Greatest power achieved during the concentric phase |
| Concentric Peak Power REL (W) | Greatest power achieved during the concentric phase relative to the athletés weight |
| Concentric Peak Velocity (m/s) | Greatest velocity achieved during the concentric phase |
ABS, absolute; COM, center of mass; Dec, deceleration; REL, relative; RSImod, reactive strength index modified; vGRF, vertical ground reaction force.