Validity and reliability of free software for bidimensional gait analysis

TL;DR

This study evaluates the validity and reliability of CvMob, a free, easy-to-use videogrammetry tool, for two-dimensional gait analysis, showing high accuracy for linear measures and knee angles but limitations for hip and ankle angles.

Contribution

It demonstrates that CvMob is a reliable and valid free tool for 2D gait analysis, especially for linear and knee joint measurements, offering a low-cost alternative for clinical use.

Findings

Strong correlation (rs mean = 0.988) between CvMob and Vicon systems.

Good agreement in knee joint angles and stride length.

Limitations in hip and ankle angle measurements.

Abstract

Despite the evaluation systems of human movement that have been advancing in recent decades, their use are not feasible for clinical practice because it has a high cost and scarcity of trained operators to interpret their results. An ideal videogrammetry system should be easy to use, low cost, with minimal equipment, and fast realization. The CvMob is a free tool for dynamic evaluation of human movements that express measurements in figures, tables, and graphics. This paper aims to determine if CvMob is a reliable tool for the evaluation of two dimensional human gait. This is a validity and reliability study. The sample was composed of 56 healthy individuals who walked on a 9-meterlong walkway and were simultaneously filmed by CvMob and Vicon system cameras. Linear trajectories and angular measurements were compared to validate the CvMob system, and inter and intrarater findings of the same measurements were used to determine reliability. A strong correlation (rs mean = 0.988) of the linear trajectories between systems and inter and intrarater analysis were found. According to the Bland-Altman method, the angles that had good agreement between systems were maximum flexion and extension (stance and swing) of the knee and dorsiflexion range of motion and stride length. The CvMob is a reliable tool for analysis of linear motion and lengths in two-dimensional evaluations of human gait. The angular measurements demonstrate high agreement for the knee joint; however, the hip and ankle measurements were limited by differences between systems.