The error is most commonly shown if the Body Weight interval cannot be detected. The body weight calculation influences the detection of phases and calculation of impulse-based parameters.

If the Body Weight interval is not detected, check your vertical force data to see if one of the following scenarios occurred:

Scenario #1: There is no 0.5 interval of stabilization before the athlete begins jumping or after the athlete is finished jumping.

What happened?

The athlete did not stabilize long enough before or after jumping for body weight to be detected.

How to fix it:

Instruct your athlete to stand still on the force plate for at least 0.5 seconds before beginning to jump.

Additional tips: The body weight interval is calculated from the beginning of the record to the beginning of the first jump. If body weight cannot be calculated in this interval, it is calculated from the end of the last jump to the end of the record. The body weight interval is detected when the total vertical force stays within 5% within the mean for 0.5 seconds.

Scenario #2: The vertical force (Fz) time series data reads <0 N during the flight phase for the jump and 0 N when body weight should be detected.

What happened?

Someone was standing on the force plate when while the force plates were zeroed before a measurement, which occurs during the “Activating Hardware” screen before recording.

How to fix it:

Instruct your athletes to stand off the force plate while activating hardware before a measurement.