Decembers exercise of the month happens to be my favorite tricep exercise. The tricep consists of three heads-medial, long and the lateral head. The lateral head generally gets the most love from exercises like push downs and presses, but the long head is mostly left out. The long head is on the inside of tricep closest to your armpit. I like to do this exercise with the rope attachment on the bottom of a pulley cable. Next, I like to place a seat with a back right in front the pulley facing outwards. Sit facing away from pulley keeping your elbows overhead and close to your ears. Lower your forearm behind your upper arm by flexing the elbows. Once lowered raise the rope back up by extending the elbow and twisting the rope at the top. Make sure you get enough depth at the bottom to really hit the triceps!
Below is a sample routine I like to use for this exercise:
Do 5 sets of 8 reps taking 1 minute rest between sets. After finishing the last set drop the weight by 15 lbs and do a burn out set to failure.