Variability and Similarity of Gait as Evaluated by Joint Angles: Implications for Forensic Gait Analysis

• NCJ Number: 246613
• Journal: Journal of Forensic Sciences Volume: 59 Issue: 2 Dated: March 2014 Pages: 494-504
• Author(s): Sylvia X.M. Yang; Peter K. Larsen Ph.D.; Tine Alkjær Ph.D.; Erik B. Simonsen Ph.D.; Niels Lynnerup Ph.D.
• Date Published: March 2014
• Length: 11 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

Closed-circuit television CCTV footage is used in criminal investigations to compare perpetrators with suspects. Usually, incomplete gait cycles are collected, making evidential gait analysis challenging.

Abstract

Closed-circuit television CCTV footage is used in criminal investigations to compare perpetrators with suspects. Usually, incomplete gait cycles are collected, making evidential gait analysis challenging. This study aimed to analyze the discriminatory power of joint angles throughout a gait cycle. Six sets from 12 men were collected. For each man, a variability range VR mean +/- 1SD of a specific joint angle at a specific time point a gait cycle was 100 time points was calculated. In turn, each individual was compared with the 11 others, and whenever 1 of these 11 had a value within this individual's VR, it counted as positive. By adding the positives throughout the gait cycle, we created simple bar graphs; tall bars indicated a small discriminatory power, short bars indicated a larger one. The highest discriminatory power was at time points 60-80 in the gait cycle. We show how our data can assess gait data from an actual case. Abstract published by arrangement with Wiley.