> ## 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.

# Peak Upper Arm Velocity

> The instant of peak upper arm forward angular velocity, used to determine forward kinematic sequence.

## Technical Details

* **Variable Type:** Event
* **Data Type:** Integer
* **Units:** Frame number
* **Column Name:** \`\`
* **Required for QA:** False
* **Measurement:** Frame at which the upper arm segment reaches its peak forward angular velocity

## Description

Peak Upper Arm Velocity marks the instant when the upper arm reaches its maximum forward angular velocity (somersaulting in the serve direction).
It is used together with [Peak Torso Velocity](/biomechanics/activities/tennis/events/peak-torso-velocity) and [Peak Forearm Velocity](/biomechanics/activities/tennis/events/peak-forearm-velocity) to determine the [Forward Kinematic Sequence](/biomechanics/activities/tennis/metrics/forward-kinematic-sequence)—the order in which segments reach their peak (optimal: torso → upper arm → forearm).

## Use Cases

* Forward kinematic sequence determination
* Timing of segment peak velocities
* Technique and sequencing analysis