> ## 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.

# Cervical Flexion/Extension

> Biomechanical analysis of cervical spine flexion and extension range of motion assessment.

## Overview

Cervical flexion/extension evaluates the range of motion and quality of movement in the neck during forward and backward bending. This assessment provides valuable information about cervical spine mobility and function.

## Instructions

From a standing position facing forward, flex the neck bringing your chin close to your chest and hold for \~1 second.
Then extend your neck and look up as far as possible, also holding for \~1 second, before returning to the starting position.
Keep your back straight and shoulders square during the motion.

## Example Videos

<Frame>
  <video controls src="https://uplift-docs-assets.s3.amazonaws.com/range_of_motion/range_of_motion-cervical_flexion_extension_combined.mp4" />
</Frame>

## Dimensions

Required inputs for processing:

* **None**

## Generic Outputs

Every capture includes session metadata, standard joint angle/velocity time series, and 3D keypoint positions common to all movements. See [Generic Outputs](/biomechanics/activities/generic_outputs) for the full list.

## Discrete Metrics

| Metric                        | Units   | Description                              | Column Name                                             |
| ----------------------------- | ------- | ---------------------------------------- | ------------------------------------------------------- |
| MaxFlexion                    | degrees | Maximum cervical flexion (90° offset)    | `cervical_peak_flexion`                                 |
| MaxExtension                  | degrees | Maximum cervical extension (90° offset)  | `cervical_peak_extension`                               |
| FlexionExtensionROM           | degrees | Total range of motion                    | `cervical_flexion_extension_range_of_motion`            |
| MaxFlexionSufficient          | -       | Whether flexion is sufficient (≥ 45°)    | `functional_cervical_flexion`                           |
| MaxExtensionSufficient        | -       | Whether extension is sufficient (≥ 70°)  | `functional_cervical_extension`                         |
| FlexionExtensionROMSufficient | -       | Whether total ROM is sufficient (≥ 115°) | `functional_cervical_flexion_extension_range_of_motion` |

## Notes

* Measurements are based on FreeHeadAngleWRTTrunkXYZ.X with 90° offset
* Sufficient flexion is defined as ≥ 45°
* Sufficient extension is defined as ≥ 70°
* Sufficient total ROM is defined as ≥ 115°