《黄帝内经·素问·刺腰痛》
足太阳经脉发病使人腰痛，痛时牵引项脊尻背，好像担负着沉重的东西一样，治疗时应刺其合穴委中，即在委中穴处刺出其恶血。
足太阳脉令人腰痛，引项脊尻背如重状，刺其郄中。太阳正经出血，春无见血。
If the foot Taiyang meridian becomes affected, it will cause a backache. The pain can extend to the neck, spine, and buttocks, making the patient feel like they are carrying a heavy object. To treat this, puncture the Weizhong acupoint, which is located in the crease behind the knee, and drain the toxic blood.