> ## 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 Forward Drift

> If the body drifts too far forward after the serve.

## Technical Details

* **Variable Type:** Movement Flag
* **Data Type:** Integer
* **Units:** N/A
* **Column Name:** `landing_phase_excessive_forward_drift`
* **Optimal Direction:** Lower is better
* **Unknown Value:** -1
* **Measurement:** Forward (fore/aft) body displacement between [Apex](/biomechanics/activities/tennis/events/apex) and [Termination](/biomechanics/activities/tennis/events/termination), normalized by athlete height
* **Threshold:** Forward displacement greater than 50% of height

## Description

Landing phase excessive forward drift is a binary indicator that flags if the body moves forward (into the court, in the serve direction) by more than 50% of the athlete's height directly after the serve.
This can indicate a lack of balance and control on landing.

## Use Cases

* Landing balance and control assessment
* Injury risk identification