The muscular increasing effect of glabra polyphenol extracted from licorice

INTERVENTION: In active group, participants take 1 capsule with 300mg Licorice Glabra Polyphenol after meal once a day for 16 weeks. In placebo group, participants take 1 placebo capsule after meal once a day for 16 weeks. CONDITION: Osteoarthritis of the knee PRIMARY OUTCOME: Muscle mass of the body SECONDARY OUTCOME: JKOM score, JOA score, stabilograph INCLUSION CRITERIA: (1)Patients who rehabilitate osteoarthritis of the knee (2) Those whose age at the time of informed consent is 20 and over. (3) Those who can understand the purpose and the contents of this study, and can agree with participation by letter.