> ## 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 Knee Flexion

> Maximum knee flexion angle over a given phase.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** degrees
* **Column Name:** Varies by phase and side; see Events/Phases
* **Aggregation:** mean
* **Precision:** 0
* **Optimal Direction:** Higher is better
* **Measurement:** Maximum knee flexion angle or maximum knee flexion velocity during the specified phase

## Events / Phases

* **At Takeoff:** Maximum knee flexion during the jumping phase ([Initiation](/biomechanics/activities/jump/events/initiation) to [Takeoff](/biomechanics/activities/jump/events/takeoff)). Column examples: `jumping_left_knee_peak_flexion_angle`, `jumping_right_knee_peak_flexion_angle` (bilateral); `jumping_knee_peak_flexion_angle` (single-leg).
* **At Landing:** Maximum knee flexion during the landing absorption phase ([Landing](/biomechanics/activities/jump/events/landing) to [Landing Bottom](/biomechanics/activities/jump/events/landing-bottom)). Column examples: `landing_left_knee_peak_flexion_angle`, `landing_right_knee_peak_flexion_angle` (bilateral); `landing_knee_peak_flexion_angle` (single-leg).

## Description

Peak knee flexion can refer to the maximum knee flexion angle during takeoff or landing.
It indicates loading depth and absorption; adequate landing flexion is associated with softer landings and lower injury risk.
The side or phase determines which column name applies.

## Use Cases

* Knee contribution and loading depth
* Landing quality and stiff-knee-landing assessment
* ACL and knee injury risk screening