Both extrinsic factors (training volume, floor hardness, and footwear) and intrinsic factors (muscle strength, flexibility, and lower limb alignment) contribute to the development of patellar tendinitis. In sports like badminton, which involve repeated sudden changes in direction and jump-landing, tensile forces equivalent to eight times one's body weight can be momentarily applied to the patellar tendon. Weakness of the hip abductor muscles or excessive pronation of the foot concentrates asymmetric loads on the medial side of the patellar tendon, accelerating injury. From a Korean medicine perspective, the flexibility and elasticity of muscles and tendons are maintained when the body's blood is sufficiently supplied. If this blood is depleted due to excessive exercise or lack of sleep, the tendons dry out, become stiff, and weakened by external impacts. The same result occurs if the muscles lack nutrients due to weak digestive function. At Dongjedang, we promote the circulation of Qi and blood around the patellar tendon using acupuncture and moxibustion, while strengthening the tendons from within with constitution-tailored herbal medicine that nourishes the tendons and reinforces digestive function.