Sling Exercise for Chronic Low Back Pain: A Systematic Review and Meta-Analysis Yue, Yu-Shan ; Wang, Xu-Dong ; Xie, Bin ; Li, Zhong-Han ; Chen, Bing-Lin ; Wang, Xue-Qiang ; Zhu, Yi Abstract Publication: PLoS ONE Pub Date: June 2014 DOI: 10.1371/journal.pone.0099307 Bibcode: 2014PLoSO...999307Y