This exercise strengthens the upper arm by targeting the triceps brachii. The exercise involves a single fluid joint movement instead of movement by multiple joints, targeting the single muscle more effectively through isolated mechanics. Lying extensions with one arm are usually auxiliary utility exercises, placing higher relative intensity on the triceps brachii head. The extension produces movement away from the center of the body by means of concentric muscle contractions. The muscles that stabilize the extension include the anterior deltoid, the posterior deltoid, the clavicular pectoralis major, the sternal pectoralis major, the teres major, the latissimus dorsi and the flexor and extensor carpi ulnaris. For best results, begin with 2-3 sets of 8-10 repetitions. Gradually increase repetitions and sets until 4-5 sets of 10-15 repetitions become a standard part of the routine. For tension relief, extend the arms between repetitions and pull the weights toward the upper chest as needed.
How to perform the lying one arm extension
Lie on a flat bench with a dumbbell in your left hand, straighten your arm so that the weight is above your shoulder, now reach across to your right arm, to help brace your left arm, with your palm facing in, and without moving your upper arm, lower the dumbbell until it reaches the side of your head. Press the weight back up above you to the starting position.
Lying One Arm Extension