> ## 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.

# Release Phase Elbow Not Straight

> Binary indicator if the non-dominant elbow is not straight enough at ball toss.

## Technical Details

* **Variable Type:** Movement Flag
* **Data Type:** Integer
* **Units:** N/A
* **Column Name:** `release_phase_elbow_not_straight`
* **Optimal Direction:** Lower is better
* **Unknown Value:** -1
* **Measurement:** Non-dominant elbow flexion angle at [Ball Release](/biomechanics/activities/tennis/events/ball-release)
* **Threshold:** Non-dominant elbow flexion angle greater than 30°

## Description

Release phase elbow not straight is a binary indicator that flags when the non-dominant (tossing) elbow is bent more than 30° at the instant of ball release.
Releasing the ball with a bent elbow can reduce the consistency and height of the ball toss.

## Use Cases

* Toss arm mechanics assessment
* Mechanics evaluation