2.1. Study Design
This was a randomized, double-blind, placebo-controlled study. The study protocol was approved by the independent ethics committee of the Kobuna Orthopedic Clinic on 28 February 2022 (approval no. MK-2202-01) and registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; UMIN000047137). The study was performed in compliance with ethical principles based on the Declaration of Helsinki and the Ethical Guidelines for Epidemiological Studies (Notification of the Ministry of Education, Culture, Sports, Science and Technology and the Ministry of Health, Labour and Welfare). The clinical trial was conducted from 28 March to 2 July 2022 at the Japan Sports Vision Association (Tokyo, Japan).