“…After deduplication and screening phases, 19 studies (Ji et al, 2007 ; Junhai et al, 2008 ; Yongsong et al, 2011 ; Li et al, 2012 , 2014 ; Guoqiang et al, 2014 ; Jialiang et al, 2014 ; Tao et al, 2015 ; Lin and Xianmo, 2017 ; Yijun et al, 2017 ; Makary et al, 2018 ; Lee et al, 2019 ; Tu et al, 2019 ; Xiang et al, 2019 ; Yan et al, 2019 ; Kim et al, 2020 ; Lan et al, 2020 ; Liu et al, 2020 ; Yu et al, 2020 ) between 2007 and 2020 were incorporated in this review ( Table 1 ). Among the articles, 14 studies were performed in China (Ji et al, 2007 ; Junhai et al, 2008 ; Yongsong et al, 2011 ; Li et al, 2012 , 2014 ; Guoqiang et al, 2014 ; Jialiang et al, 2014 ; Tao et al, 2015 ; Lin and Xianmo, 2017 ; Yijun et al, 2017 ; Xiang et al, 2019 ; Yan et al, 2019 ; Lan et al, 2020 ; Liu et al, 2020 ), three were conducted in the USA (Tu et al, 2019 ; Kim et al, 2020 ; Yu et al, 2020 ), and two were conducted in South Korea (Makary et al, 2018 ; Lee et al, 2019 ). Five kinds of diseases were involved in these studies: chronic low back pain (Li et al, 2014 ; Tu et al, 2019 ; Xiang et al, 2019 ; Yan et al, 2019 ; Kim et al, 2020 ; Yu et al, 2020 ), non-specific low back pain (Makary et al, 2018 ; Lee et al, 2019 ), lumbar disc herniation (Yongsong et al, 2011 ; Guoqiang et al, 2014 ; Jialiang et al, 2014 ; Tao et al, 2015 ; Lin and Xianmo, 2017 ; Yijun et al, 2017 ; Lan et al, ...…”