> ## 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.

# Contact Phase Wrist Height

> Height of the wrist at apex (ball contact) measured from the ground.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** meters (m)
* **Column Name:** (implementation-specific)
* **Measurement:** Vertical height of the dominant-side wrist joint center above the ground at [Apex](/biomechanics/activities/tennis/events/apex) (ball contact)

## Description

Contact phase wrist height is the height of the wrist at ball contact. It reflects contact point and can indicate consistency of toss and strike height.

## Use Cases

* Contact point consistency
* Toss and strike height
* Comparison across players or trials