> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplift.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Pelvis Velocity Initiation (Launch)

> The start of pelvis rotation - also known as launch event. Determined as the leading edge of the pelvis angular velocity waveform. This marks the beginning of the power generation phase.

## Technical Details

* **Variable Type:** Event
* **Data Type:** Integer
* **Units:** Frame number
* **Column Name:** `pelvis_initiation_frame`
* **Detection Method:** Last local minimum before peak pelvis angular velocity
* **Alternative Name:** Launch event

## Description

The pelvis velocity initiation event marks the beginning of the power generation phase when the pelvis starts rotating.
This is often called the "launch" event and is critical for understanding the kinetic chain sequence.

## Use Cases

* Power generation analysis
* Kinetic chain evaluation
* Swing timing assessment
* Launch position measurements