> ## 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.

# Global Trunk Flexion at P4 Top of Swing

> Trunk forward/backward flexion angle relative to the global (vertical) reference frame, at P4 Top of Swing.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** deg
* **Column Name:** `global_trunk_flexion_at_p4`
* **Aggregation:** mean
* **Precision:** 0
* **Optimal Direction:** N/A
* **Measurement:** Trunk flexion angle in the global reference frame, sampled at the P4 Top of Swing event

## Description

Global Trunk Flexion at P4 Top of Swing reports the trunk forward/backward flexion angle relative to the global (vertical) reference frame, sampled at the P4 Top of Swing event. Global angles are expressed relative to the ground/vertical reference frame rather than a body-relative axis, making them comparable across different camera setups.

## Use Cases

* Global posture assessment
* P4 Top of Swing position analysis