Visual analogue scale (VAS)
KOA, pain
It is a subjective scale that is bidirectional and used for pain measurement. It consists of a 10 cm line labeling on both sides parallels. It starts with a line indicating the least “no pain” and ends with a line that indicating most “worst pain”. Every patient rated their pain on VAS. The distance between the “no pain” anchor and the patient’s mark was measured on the 10-cm line through a ruler to record VAS scores. A higher score indicates greater pain intensity. It is considered the most reliable and stable pain measurement scale. It has the least measurement error and minimal detectable change values for the pain of KOA [