The Pull-up Is A Muscular Resistance That Primarily Works Which Muscle Group?

Pullups are a simple but remarkable effective exercise for working out the muscles of your back. This exercise requires you to pull up your body to a bar until your chest is level with it and then come back down. This can be carried out for a number of repetitions. The back contains a number of large muscles that must work extensively to carry the entire body weight during these routines. In addition, a variety of muscles in your shoulders and arms also play important roles in carrying out a pullup.

Latissimus Dorsi

The latissimus dorsi is the most important muscle used in pullups. This muscle is one of the largest muscles in the human body. The lats are triangular in shape and take origin from the bones of the spine, clavicle and shoulder blades. The muscles inserts into the humerus, the bone of the arm. As the muscle contracts, the shoulders go backward, which is a motion called extension. During pullups, this muscle acts to bring the arms backward, which is needed to raise the body up to the bar.

Trapezius

The trapezius is another muscle that is essential to pullups. This muscle originates from the back of the skull and from the spine; it inserts into the shoulder blades. Each muscle is triangular in shape, as they come together, they form a diamond, or "trapezoid." Contraction of the muscle elevates the retract and depresses the shoulder blades.

Synergists

Synergists are muscles that assist another muscle in carrying out its activity. Synergists in both the shoulders and the arms play important roles in the pullup. The biceps brachii, brachioradialis and brachialis help flex the elbow. The levator scapulae pulls the shoulder blades away from the trunk; and the rhomboids and teres major keep the arms arm from going outward. Other synergists include the pectoralis major and minor. The triceps is a "dynamic stabilizer" and helps keep the joints by countering rotational forces.

Pullups Tips

Avoid relaxing your muscles too much after coming down from a pullup because this can put excess strain on your shoulder joints and make it difficult for you to come back up. Keeping your arms far apart makes pullups more difficult and place more stress on your lats. The difficulty of pullups can also be increased by using a weight tied around the around the waist. "Underhand" pullups places more stress on your biceps. If you are unable to carry your entire body weight in pullups, try using assistance, or alternatively perform "pull-downs," which use the same muscles.