[Myofascial trigger point: an indicator of acupoint sensitization].

OBJECTIVE: The present study is to investigate the characteristic distribution of primary pain points and referred pain areas in patients with knee-joint pain diseases, therefore revealing the correlation between the myofascial trigger point and acupoint sensitization. METHODS: A total of 483 patients (320 men and 163 women, 36 to 72 years in age) with knee-joint pain recruited from 4 clinical centers were observed from July, 2017 to April, 2019 in the present study. The areas of primary and referred pain in these patients were detected by thumb-pressing and marked on human anatomic atlas. RESULTS: Of the 483 enrolled participants, 336 had lesion sites or tender points around the injured knee joint, and 147 with myofascial pain syndrome showed referred pain spots (zones) in the knee joint area. In 105 patients with patellar tendonitis, epiphysitis of the tibial tubero-sity, or quadriceps tendonitis, the pain area was mainly distributed in the anterior region of the knee. In 76 patients with medial collateral ligament injury, medial meniscal lesion, goose foot bursitis or semimembranosus ending-point inflammation, the pain points mainly occurred in the medial area of the knee. In 127 patients with lateral collateral ligament, lateral meniscus lesion, iliotibial band tendonitis, popliteus or triceps tendinitis, the pain spots were found in the lateral region of the knee. In 28 patients with posterior cruciate ligament injury or popliteal fossa tendonitis, the local pain was found to be at the back of the knee. Referred pain areas were normally detected in the lateral femoral muscles (43 cases), anterior femoral muscles (39 cases), adductor group of femur (26 cases), posterior popliteal fossa muscles group (15 cases), hamstrings (13 cases) and medial leg (11 cases)．. CONCLUSION: The primary pain areas or spots of the knee injury mainly distribute around the joint, whereas those of each muscle group lesion are often located in their respective skeletal muscle. Most of the referred pain areas often occur in the distal end of skeletal muscle and around the knee joint. Primary myofascial trigger points may be considered to be an indicator of acupoint sensitization.

[Correlation Between Referred Pain Region and Sensitized Acupoints in Patients with Stable Angina Pectoris and Distribution of Sensitized Spots in Rats with Myocardial Ischemia].

OBJECTIVE: To observe the correlation between the referred pain regions of stable angina pectoris (SAP) and the acupoints in coronary heart disease (CHD) patients and to investigate the rule of regional sensitized point distribution in rats. METHODS: A total of 1 046 CHD patients with SAP from 8 hospitals in China were recruited in the present study. The tenderness was palpated along the left and right chest, back, shoulder, upper limb, etc. by a specially-assigned researcher in each hospital. Among them, 77 patients accepted pain threshold (PT) measurement by using a hand-held esthesiometer. In animal experiments, 14 SD rats were subjected to occlusion of the left anterior descending branch of the left coronary artery for 4 h for establishing myocardial ischemia (MI) model, and other 4 normal rats were used as the sham-operation control group. Four hours after MI, all the rats accepted tail venous injection of 5% Evans blue (50 mg/kg) for examining the distribution of the blue dye exudation spots at the body surface where the mechanical PT was also detected by a von Frey. RESULTS: In 1 046 CHD patients, 987 (94.36%) were found to have at least one tenderness spot. The tenderness spots were found at the left chest (87.47%), right chest (13.67%), left arm (ulnar side, 41.30%), right upper limb (4.68%), left shoulder back (30.21%), right shoulder back (7.07%), etc., accompanied with rash or pigmentation, subcutaneous induration, cord-like tissue contracture, skin sag, etc. The mechanical PT level was significantly lower at the tenderness spots of the left upper limb than at non-tender points of the right upper limb in CHD patients (P<0.001). Tenderness and cutaneous abnormal changes in angor pectoris patients distributed mostly on the left chest, back, shoulder and upper limb, and some also on the right. Tender points scattered on, near or outside acupoints. A similar distribution of the blue exudation spots and lower mechanical PT spots were found in MI rats, but not in sham-MI rats. CONCLUSION: In the case of MI, a regular "referred sensitization" response frequently occurs in the dermatomere area innervated by the corresponding segments (T 1－T 5) in both CHD patients and MI rats, which may be closely associated with the formation of acupoints in ancient China.