BICEPS BRACHII MYOLOGY

OVERVIEW

The Biceps Brachii muscle is a strong biarticular muscle bridging the shoulder and elbow joint. Located on the anterior aspect of the upper arm, it is a long fusiform muscle composed of two heads, a laterally located long head and a medially located short head. The short head of the biceps originates from the apex of the coracoid process of the scapula via a flat tendon while the long head originates from the supraglenoid tubercle of the scapula via a long cylindrical tendon. The bellies and fibers of the two heads travel down the arm, crossing over the elbow, and converging into a single tendon the inserts on the radial tuberosity of the radius. Because of these attachment sites, direction of the fibers, and the joints involved, the biceps are responsible for shoulder flexion, elbow flexion, and forearm supination. The long head can also participate in shoulder abduction.

NICKNAME

"Biceps"

LOCATION

Anterior, superficial aspect of the humerus.

ORIGIN

Short head - The short head of the biceps originates from the apex of the coracoid process of the scapula via a flat tendon.
Long head - originates from the supraglenoid tubercle of the scapula via a long cylindrical tendon.

INSERTION

The fibers of the biceps brachii run inferiorly from its sites of origin and converge into single tendon that inserts on the radial tuberosity of the radius.

FUNCTION

Shoulder Flexion
Elbow Flexion
Forearm Supination
Glenohumeral Stabilization
Shoulder Abduction (long head)
Shoulder Transverse Adduction (short head)

SHORT AND LONG POSITION

Because the two heads have different origination sites, the short and long position of this muscle will vary slightly depending on which head one is attempting to target. The short position of this muscle can be found when the insertion site is closest to one of its origination sites. The long position of this muscle can be found when the insertion site is furthest from one of its origination sites.

SHORT HEAD

The short position of the Short Head of the Bicep can be found when taking the following steps:

Standing in anatomical position, the forearm should already be supinated (palm of the hand facing forward or "up"),
Perform elbow flexion (bend at the elbow),
Perform shoulder flexion (lift the elbow while bent until elbow is approximately shoulder height),
Perform transverse adduction at the shoulder (pull the elbow in across the body to a natural degree without excessive scapular movement),
Internally rotate the arm at the shoulder joint (let the hand rotate toward the collar bone).

This is the short position for the Short Head of the Biceps Brachii. Keep the upper arm in this position as you perform curls.

The long position of the Short Head of the Bicep can be found when the above steps are performed almost to the contrary.

Standing in anatomical position with the forearm supinated, pronate the forearm instead to place the palm in a "downward" facing position (only to a degree at which the humerus does not internally rotate),
Keep the elbow in extension (straight elbow),
Perform shoulder extension (only to a degree where the shoulder does not roll up and forward),
Abduct the entire straight arm to approximately 45° (you'll probably start feeling a stretch on the bicep),
Do not worry about externally rotating.

This is the long position for the Short Head of the Biceps Brachii. Maintain this upper arm position as you perform curls. Pronation is optional. However, if you choose to pronate at the end of each rep, make sure you supinate as you curl. Failing to do so will recruit Brachioradialis and Brachialis rather than Biceps Brachii.

LONG HEAD

The short position of the Long Head of the Bicep can be found when taking the following steps:

Standing in anatomical position, the forearm should already be supinated (palm of hand facing forward or "up"),
Perform elbow flexion (bend at the elbow),
Perform shoulder abduction in the scapular plane (lift the elbow while bent until the arm is as high as it can go without elevating the shoulder).

This is the short position for the Long Head of the Biceps Brachii. Keep the upper arm in this position as you perform curls.

The long position of the Long Head of the Bicep can be found when the above steps are performed almost to the contrary.

Standing in anatomical position with the forearm supinated, pronate the forearm instead to place the palm in a "downward" facing position (only to a degree at which the humerus does not internally rotate),
Keep the elbow in extension (straight elbow),
Perform shoulder adduction in the scapular plane (only to a degree where the shoulder does not roll up and forward).

This is the long position for the Long Head of the Biceps Brachii. Maintain this upper arm position as you perform curls. Pronation is optional. However, if you choose to pronate at the end of each rep, make sure you supinate as you curl. Failing to do so will recruit more Brachioradialis and Brachialis than Biceps Brachii.

BOTH HEADS

Although we can emphasize the heads individually, they don't function in complete isolation. Depending on our gym schedule, allotted time in the gym, and our goals, emphasizing each head may not be practical. Finding a happy medium between the short and long positions of both exercises, we can come to an inclusive long position for the Biceps Brachii and an inclusive short position for the Biceps Brachii that will target both heads.

The inclusive short position of the Biceps can be found when taking the following steps:

Standing in anatomical position, the forearm should already be supinated (palm of hand facing forward or "up"),
Perform elbow flexion (bend at the elbow),
Perform shoulder flexion (lift the elbow while bent until elbow is approximately shoulder height).

This is the inclusive short position for the Biceps Brachii that targets Both Heads. Keep the upper arm in this position as you perform curls.

The inclusive long position of the Biceps can be found when the above steps are performed almost to the contrary.

Standing in anatomical position with the forearm supinated, pronate the forearm instead to place the palm in a "downward" facing position (only to a degree at which the humerus does not internally rotate),
Keep the elbow in extension (straight elbow),
Perform shoulder extension (only to a degree where the shoulders do not roll up and forward).

This is the inclusive long position for Biceps Brachii that targets Both Heads. Maintain this upper arm position as you perform curls. Pronation is optional. However, if you choose to pronate at the end of each rep, make sure you supinate as you curl. Failing to do so will recruit more Brachioradialis and Brachialis than Biceps Brachii.

ANTAGONIST

Triceps Brachii: While there are two heads of the Biceps Brachii and three heads of the Triceps Brachii, a secondary muscle called the Brachialis sits under the Biceps Brachii to correspond perfectly with the Triceps Brachii. Below are the antagonist muscles of the Biceps Brachii and the muscles of the upper arm.

Short Head of Biceps = Lateral Head of Triceps
Long Head of Biceps = Long Head of Triceps
Brachialis = Medial Head of Triceps