A primer on anatomy - Part 5

The rotator cuff muscles — or articular muscles of the shoulder — are involved in abduction, adduction, and rotation of the humerus.

The external rotators are usually neglected, and are trained by the L-fly.


The large, kite-shaped muscle that connects the skull, scapulae, clavicles, and some upper vertebrae. It retracts, elevates, depresses and rotates the scapula, and extends the head (moves it rearward). The trapezius is abbreviated to traps.

Exercises that train the trapezius include shrugs, rows, and the deadlift and its variations. The neck extension works the upper traps.


The muscle at the sides of the neck, connecting the sternum and clavicles to the skull. Acting together, both sides of the sternocleidomastoid flex the head and neck; when acting separately, each muscle produces rotation and lateral flexion.

The four-way neck machine is the preferred exercise for this muscle.


The shoulder cap muscle, and a prime mover of the humerus — it abducts, flexes, extends, and rotates the humerus. It has three heads: anterior, medial, and posterior. The deltoids are abbreviated to delts.

Exercises that train the deltoids include the dumbbell press, barbell press, and lateral raise.

Biceps brachii

The two-headed muscle (long, and short heads) of the front or anterior surface of the arm, which connects the upper scapula to the radius and forearm muscle, and flexes the forearm and thus the elbow joint, and supinates the forearm. The biceps are abbreviated to bis.

Exercises that train the biceps include curls, pulldown, and rows.


The muscle of the front of the arm beneath the biceps, which connects the humerus to the ulna, and flexes the forearm and elbow joint.

Exercises that train the brachialis include curls, pulldown, and rows.

Triceps brachii

The three-headed muscle (long, medial, and lateral heads) on the rear or posterior surface of the arm, which connects the humerus and scapula to the ulna, and extends the forearm (and the elbow joint). Just the long head of the triceps adducts the arm. The triceps are abbreviated to tris.

Exercises that train the triceps include bench presses, presses, parallel bar dips, and the pushdown.


The anterior surface (palm side) has eight muscles spread over three layers, most of which are involved in flexing the wrist and fingers. The posterior surface has ten muscles spread over two layers, involved in extending the wrist and moving the fingers.

Timed hold, deadlifts, shrugs, grippers, rows, pulldown, and finger extension train the forearms, along with all exercises that work the grip.

Whenever you think that it's tough to deliver on all the components for training success, remind yourself that having the good fortune to be able to dedicate yourself to training and everything that should go with it, is a privilege. Eventually, you won't be able to train hard, or dedicate yourself to anything, so make the most of the present — no slacking, no corner cutting, and no excuses.

Get to work! Make the most of your opportunity to train and achieve physical improvement.

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