# Non-dominant leg joints bear greater loading during balance beam walking in 4-year-old children

## TL;DR

Four-year-old children use their non-dominant leg more during balance beam walking, which could help assess their motor development.

## Contribution

The study reveals asymmetrical joint loading strategies in young children during balance beam walking.

## Key findings

- Non-dominant hip joints show increased medial force during balance beam walking.
- Non-dominant knee joints show reduced lateral force during the swing phase.
- Slower medial-to-lateral transitions occur in non-dominant joints during balance beam walking.

## Abstract

Dynamic balance is a critical foundation for the development of motor skills in early childhood. Functional tasks such as beam walking pose a significant challenge to the frontal plane stability of preschool children. However, the mechanisms by which young children regulate hip, knee, and ankle joint loading under such conditions remain unclear. Therefore, this study aimed to explore the regulatory strategies of lower limb joint reaction forces during beam walking in 4-year-old children.

Fourteen healthy 4-year-old children participated in overground walking (OGW) and balance beam walking (BBW). A markerless motion capture system, OpenCap, was used to collect kinematic data. Joint reaction forces in the frontal plane for the dominant and non-dominant at the hip, knee, and ankle were computed using OpenSim. One-dimensional time series parameters of joint reaction forces were used to assess loading characteristics between OGW and BBW.

Under BBW, the medial reaction force at the non-dominant hip joint significantly increased during multiple phases of the gait cycle, and the lateral force at the non-dominant knee joint decreased during the swing phase, with slower medial-to-lateral transitions.

In functional walking tasks, asymmetry in lower limb joint loading between the dominant and non-dominant legs may serve as a sensitive indicator for assessing the neuromuscular development and gait control strategies in preschool children.