Clinical observation on distribution characteristics and rules of pain sensitivity points on body surface in patients with knee osteoarthritis

OBJECTIVE To observe the distribution characteristics and rules of pain sensitivity points on body surface in patients with knee osteoarthritis (KOA). METHODS A total of 916 patients with KOA were selected in this study, the pain sensitivity points of local site of knee joint were probed by thumb palpation. Tape was used to measure the distance between the pain sensitivity points and the most nearby acupoints. The Wagner tenderness measuring instrument was used to measure the tenderness threshold of pain sensitivity points. RESULTS A total of 3618 pain sensitivity points were probed, among them, 3338 pain sensitivity points were sensitized. The minimum sensitization degree was 1.00, the maximum sensitization degree was 3.39, while the average sensitization degree was (2.16±0.60). Pain sensitivity points were distributed 0.37-1.73 cun around the acupoints, the average distance was (1.26±0.20) cun. Most of the pain sensitivity points (48.7%) were around Yingu (KI 10), Ququan (LR 8) and Xuehai (SP 10). The number and sensitization degree of pain sensitivity points were associated with McGill pain questionnaire score of patients with KOA (P<0.001). CONCLUSION The pain sensitivity points of patients with KOA may be the expansion effect of acupoint areas in the disease states, pain sensitivity points are more likely to appear on the medial side of knee joint.