Why would bending your elbow cut off the circulation?

Bending your elbow can compress the brachial artery and associated nerves, which may reduce blood flow to the forearm and hand. This compression can occur due to the position of the arm or the presence of tight clothing. While temporary, this reduction in circulation can lead to numbness or a tingling sensation. Prolonged compression can have more serious effects, so it's important to change positions regularly.