1 Correction to: Journal of Medical and Biological Engineering (2020) 40:887–898 https://doi.org/10.1007/s40846-020-00569-w

The article “Functionally Oriented Alignment of the Lower Extremity Reflecting the Direction of Gait for Healthy Elderly, Knee Osteoarthritis, and Total Knee Arthroplasty Subjects”, written by Takashi Sato, Tomoharu Mochizuki, Ryota Katsumi and Yuki Takahashi, was originally published Online First without Open Access. After publication in volume 40, issue 6, page 887–898 the author decided to opt for Open Choice and to make the article an Open Access publication. Therefore, the copyright of the article has been changed to © The Author(s) 2021 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected.