Reliability and Validity of a 2-D Video Digitizing System during a Static and a Dynamic Task

Abstract

Context:The SMART™ software system offers low-cost kinematic analysis through digitization of video from a single camera. The reliability and validity of this product have not been reported.Objective:To assess the reliability and validity of the SMART software during a simple static task and dynamic task.Design:Test–retest to compare assumed neutral and goniometrically measured joint angles in the sagittal plane of the lower extremity.Setting:Research laboratory.Participants:7 in a static task, 16 young, physically active in a dynamic task.Results:Measurement error of the SMART system ranged from 0.29° ± 1.98° to 11.07° ± 1.77°. The interrater reliability (ICC2,1) values ranged from .60 to .92 for the static task and from .76 to .89 for the dynamic task.Conclusions:Based on the results of both studies, the SMART system offers a low-cost alternative for reporting single-plane kinematics during an individual frame of video during static stances and slow dynamic tasks with strong reliability and reasonable validity.