Flow diagram of studies through the review process Flow diagram of studies through the review process. *Five records investigated two supplements in their study. Flow diagram of studies through the review process. *Five records investigated two supplements in their study. AMED, Allied and Complementary Medicine; CENTRAL, Cochrane Register of Controlled Trials; CINAHL, Cumulative Index to Nursing and Allied Health Literature; OA, osteoarthritis; RCT, randomised controlled trial. Xiaoqian Liu et al. Br J Sports Med 2018;52:167-175 Copyright © BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine. All rights reserved.