> ## 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.

# Knee Valgus

> Medial knee displacement (valgus) of the lead leg at the bottom of the forward lunge.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** meters (m)
* **Column Name:** `lunge_forward_right_valgus_bottom`, `lunge_forward_left_valgus_bottom`
* **Aggregation:** mean
* **Precision:** 2
* **Optimal Direction:** Lower is better
* **Measurement:** Orthogonal distance of the knee joint center from the hip–foot plane at the [Bottom](/biomechanics/activities/lunge/events/bottom) event
* **Direction:** outward positive (+, varus), inward negative (−, valgus)

## Events / Phases

* **At Bottom:** Measured at the [Bottom](/biomechanics/activities/lunge/events/bottom) event for the lead (stepping) leg.
  * Column names: `lunge_forward_right_valgus_bottom` (right footedness), `lunge_forward_left_valgus_bottom` (left footedness). The non-lead leg is set to NaN.

## Description

Knee valgus measures the medial (inward) displacement of the knee joint center relative to the plane defined by the hip and foot at the deepest point of the lunge.
Negative values indicate valgus (knee caving in); positive values indicate varus (knee pushing out).
Only the lead leg is computed based on the movement's reported footedness.

## Use Cases

* Injury risk screening for the lead knee
* Movement quality and knee control during single-leg loading
* Rehabilitation and return-to-sport assessment