Muscles Used in Baseball

The various aspects of baseball -- baserunning, batting, catching, fielding and throwing -- require powerful muscle contractions throughout your body, particularly from the muscles within your abdomen, shoulders, thighs and upper arms. Understanding how these muscles function as you play the game is essential for designing and implementing an appropriate training program to enhance your performance and minimize your risk for injuries.

External/Internal Oblique

The external and internal oblique muscles span the sides of your abdomen, attaching to your lower ribs on top and to the iliac crest of your pelvis on the bottom. The external oblique helps rotate your torso to the opposite side, meaning the muscle on the left side of your abdomen contracts to turn your torso to the right and vice versa, and the internal oblique facilitates rotation to the same side. Both oblique muscles contract when you swing a bat and pitch or throw a baseball, and both movements require powerful rotational movement.

Quadriceps

The quadriceps are a group of four muscles -- the rectus femoris, vastus intermedius, vastus lateralis and vastus medialis -- that span the front of the femur, or thigh bone. They work together to extend your knee joint and the rectus femoris assists with hip flexion ranges of motion. The quadriceps play a key role when you run and sprint, so they work hard when you're chasing the ball in the infield or outfield and when you're running the bases. You also use the quadriceps if you play catcher, which requires squatting and standing repeatedly.

Rotator Cuff Muscles

The rotator cuff muscles are so named because they rotate the humerus bone within the shoulder socket and because their tendons form a cuff around the glenohumeral joint -- the main shoulder joint. They include the infraspinatus, supraspinatus and teres minor muscles, which produce external rotation, and the subscapularis muscle, which assists with internal rotation. The rotator cuff muscles are key contributors during the baseball throwing motion, which requires both external and internal rotation ranges of motion. They're also susceptible to injuries from repetitive throwing, so you should perform baseball-specific rotator-cuff strengthening exercises regularly.

Triceps Brachii

The triceps brachii muscle lies on the back of your upper arm and facilitates elbow extension ranges of motion. The muscle attaches to the ulna bone, just below your elbow, on the bottom, and then divides into three heads as it moves upward -- the lateral and medial head, which attach to the back of the humerus bone, and the long head, which attaches to the back, outer portion of the scapula bone on your upper back. The triceps contracts powerfully to extend your forearm during the acceleration phases of the baseball swing and throwing motion.