An arm bar is a common submission technique used in martial arts, particularly in Brazilian Jiu-Jitsu and MMA. It involves isolating an opponent's arm and applying pressure to the elbow joint, forcing them to submit or risk injury. The technique can be executed from various positions, including the guard or mount, and requires proper leverage and control. To perform an arm bar, the practitioner typically secures the opponent's arm between their legs while maintaining a strong grip on the wrist. By extending their hips and pulling the arm downwards, they create tension on the elbow. This move is effective for controlling an opponent and can lead to victory in competitions.