There is a pulling sensation behind the knee joint.

　　A pulling sensation at the back of the knee may be caused by physiological factors, or by pathological conditions such as knee arthritis or meniscus injury. Targeted treatment should be provided according to the specific cause. The detailed analysis is as follows:

　　I. Physiological Factors

　　If one engages in prolonged physical labor, muscles may produce a large amount of metabolic byproducts such as lactic acid, which cannot be eliminated promptly. This can easily irritate the muscles and lead to spasms, resulting in the aforementioned sensation. This is considered a normal physiological phenomenon and usually improves with rest.

　　II. Pathological Factors

　　1. Knee Arthritis

　　Patients with knee arthritis may experience local stiffness, redness, swelling, and pain due to inflammatory irritation. During physical activity, they may feel a pulling sensation in the affected area. This discomfort can be relieved through treatments such as acupuncture or massage.

　　2. Meniscus Injury

　　When the posterior horn of the knee's meniscus is injured, it may trigger an aseptic inflammation. Due to this inflammation, patients may experience local pain and a sensation of pulling. Surgical intervention may be required for treatment.

　　In addition to the above relatively common causes, other conditions such as ligament injuries, popliteal bursitis, or popliteal cysts may also be responsible. If any discomfort occurs, timely medical evaluation is recommended to ensure early diagnosis and treatment, avoiding delays that could worsen the condition.