Author ORCID Identifier

Jennifer M Yentes

Document Type

Article

Publication Date

11-3-2018

Abstract

Sample entropy (SaEn) has been used to assess the regularity of lower limb joint angles during walking. However, changing sampling frequency and the number of included strides can potentially affect the sample entropy. The present study investigated the effect of sample frequency and the number of included strides on the calculations of SaEn in joint angle signals recorded during treadmill walking. Eleven subjects walked at their preferred walking speed for 10 minutes, and SaEn was calculated on sagittal plane hip, knee and ankle angle signals extracted from 50, 100, 200, 300 and 400 strides at sampling frequencies of 60, 120, 240 and 480Hz. Increase in sampling frequency decreased the SaEn significantly for the three joints. The number of included strides had no effect on the SaEn calculated on the hip joint angle and only limited effect on the SaEn calculated on the knee and ankle joint signals. The present study suggests that the number of data points within each stride to a greater extent determines the size of the SaEn compared to the number of strides and emphasizes the use of a fixed number of data points within each stride when applying SaEn to lower limb joint angles during walking.

Comments

“This is a post-peer-review, pre-copyedit version of an article published in Medical & Biological Engineering & Computing. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11517-018-1920-2”.


© International Federation for Medical and Biological Engineering 2018

Journal Title

Medical & Biological Engineering & Computing

First Page

1

Last Page

6

Available for download on Sunday, November 03, 2019

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