> ## 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 Arm Out of Slot Position

> Binary indicator if the dominant arm is not lifted directly above the body at ball contact.

## Technical Details

* **Variable Type:** Movement Flag
* **Data Type:** Integer
* **Units:** N/A
* **Column Name:** `contact_phase_arm_out_of_slot_position`
* **Optimal Direction:** Lower is better
* **Unknown Value:** -1
* **Measurement:** [Contact Phase Shoulder Abduction](/biomechanics/activities/tennis/metrics/contact-phase-shoulder-abduction) at [Apex](/biomechanics/activities/tennis/events/apex)
* **Threshold:** Shoulder abduction less than 110° or greater than 140°

## Description

Contact phase arm out of slot position is a binary indicator that flags when the dominant shoulder is abducted outside the 110°–140° range at ball contact, indicating the arm is not in an optimal overhead "slot" position to strike the ball.

## Use Cases

* Contact position assessment
* Mechanics evaluation