# Relationship of Knee Abduction Moment to Trunk and Lower Extremity Segment Acceleration during Sport-Specific Movements

## TL;DR

This study explores using wearable sensors to estimate knee injury risk during sports movements by analyzing body segment accelerations.

## Contribution

The study introduces a novel approach using acceleration data from wearable IMUs to estimate knee abduction moments linked to ACL injury risk.

## Key findings

- Moderate correlations were found between peak KAM and segment accelerations during single-leg hop and deceleration tasks.
- Peak accelerations in the trunk, pelvis, and shank showed relationships with KAM during a 45° cut task.
- Findings suggest wearable IMUs could be used for on-field injury risk assessment.

## Abstract

The knee abduction moment (KAM) has been identified as a significant predictor of anterior cruciate ligament (ACL) injury risk; however, the cost and time demands associated with collecting three-dimensional (3D) kinetic data have prompted the need for alternative solutions. Wearable inertial measurement units (IMUs) have been explored as a potential solution for quantitative on-field assessment of injury risk. Most previous work has focused on angular velocity data, which are highly susceptible to bias and noise relative to acceleration data. The purpose of this pilot study was to assess the relationship between KAM and body segment acceleration during sport-specific movements. Three functional tasks were selected to analyze peak KAM using optical motion capture and force plates as well as peak triaxial segment accelerations using IMUs. Moderate correlations with peak KAM were observed for peak shank acceleration during single-leg hop; peak trunk, thigh, and shank accelerations during a deceleration task; and peak trunk, pelvis, and shank accelerations during a 45° cut. These findings provide preliminary support for the use of wearable IMUs to identify peak KAM during athletic tasks.