Rafael “Formiga” Barbosa shows how to attack the arm with a straight arm lock from the top position of the half guard. Brazilian Jiu-Jitsu technique.
If you are in top half guard it is pretty easy to get an arm lock. First swim your arm underneath your opponent’s far side arm to get the under hook. Now you can pressure forwards, putting all your weight over your training partner’s shoulder. Use your available leg to block your opponent’s arm by sliding your knee over his bicep so that it is trapped under your shin. Now you are ready to finish the arm lock. With your under hook arm, grab your own gi collar and lock your elbow. Notice how Formiga uses his elbow to secure his training partner’s arm tightly to his chest. From here, place your head on the mat, take your second hand and place it under your elbow, squeeze and wait for the tap.