> ## 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.

# Landing Phase Excessive Side Lean

> Leaning too far sideways after the serve.

## Technical Details

* **Variable Type:** Movement Flag
* **Data Type:** Integer
* **Units:** N/A
* **Column Name:** `landing_phase_excessive_side_lean`
* **Optimal Direction:** Lower is better
* **Unknown Value:** -1
* **Measurement:** Trunk lateral (side-to-side) tilt at [Termination](/biomechanics/activities/tennis/events/termination)
* **Threshold:** Absolute trunk tilt greater than 30° (to either side)

## Description

Landing phase excessive side lean is a binary indicator that flags if the trunk is tilted sideways more than 30° (in either direction) at the finish of the serve.
This can indicate poor deceleration control, increased lateral low back strain, and poor positioning to prepare for a return volley.

## Use Cases

* Follow-through and deceleration assessment
* Injury risk identification