# Longitudinal Alterations in the Control of Lateral Center of Mass Movement During Walking in a Patient With Unilateral Transtibial Amputation: A Case Study

## TL;DR

This case study examines how a person with a leg amputation improves their walking balance over time, focusing on center of mass control.

## Contribution

The study provides new insights into longitudinal gait adaptation and lateral center of mass control in unilateral transtibial amputation.

## Key findings

- Lateral CoM movement shifted toward the prosthetic side until the third measurement.
- Segmental coordination improved significantly by the fourth measurement.
- Enhanced gait performance delayed lateral CoM coordination improvements.

## Abstract

This study assessed longitudinal changes in the control of the center of mass (CoM) in the lateral direction through gait reacquisition in an individual with unilateral transtibial amputation (UTTA). We examined a male patient with UTTA who could walk on a parallel bar. The marker trajectories and ground reaction forces were measured every two weeks (total: four times) using an optical motion capture system and force plates. After two measurements, the samples were collected without a parallel bar. Subsequently, we evaluated the CoM movement and its segmental coordination through uncontrolled manifold (UCM) analysis. After the second measurement, the walking speed and step length increased. The lateral CoM movements gradually increased toward the prosthetic side until the third measurement. In the fourth measurement, the CoM movement towards the prosthetic side was the smallest and closest to the intact side at the end of the stance phase. In addition, segmental coordination improved significantly. Enhanced gait performance delayed the improvement of segmental coordination for CoM movement in the lateral direction.