Dance Anatomy & Kinesiology

416 Dance Anatomy and Kinesiology

Individual Muscles of the Elbow

Anterior Elbow Muscles

Three important anterior muscles that flex the elbow are the biceps brachii, brachialis, and brachio-

radialis. Some of the muscles of the forearm, wrist, and hand can also aid with elbow flexion but for

purposes of simplicity will not be discussed here. Elbow flexion is important for lifting motions, move-

ment involving bringing the hands toward the upper body, and gestural movements.

Attachments and Primary Actions of Biceps Brachii

Muscle Proximal attachment(s) Distal attachment(s) Primary action(s)

Biceps brachii

(BY-seps BRA-kee-eye)

Long head: just above

glenoid cavity of scapula

Short head: coracoid

process of scapula

Tuberosity of radius via

a common tendon

Elbow flexion

Radioulnar supination

(Shoulder flexion—long head)

(Shoulder abduction when shoulder

in external rotation—long head)

(Shoulder adduction—long head)

Biceps Brachii

As its name implies, the biceps brachii (biceps, two

heads + brachium, arm) has two heads. It is located

superficially in the front portion of the upper arm (figure

7.41). The long head originates above the glenoid cavity

on the scapula, and its tendon passes over the top of the

humerus and then runs within the intertubercular groove

of the humerus. Due to this location, the long head of

the biceps brachii can depress the head of the humerus

to help prevent impingement when forceful contraction of

the biceps brachii is required such as in resisted elbow

flexion (Schmitz and Ciullo, 1999; Smith, Weiss, and

Lehmkuhl, 1996). The short head arises from the coracoid

process of the scapula. In the proximal part of the upper

arm these muscles exist as separate bellies, but about

midway down the humerus they join to become one belly

and attach to a tuberosity on the medial side of the radius

(radial tuberosity) via a common tendon.

The biceps brachii is an important flexor of the elbow.

With its attachment onto the tuberosity of the radius,

when the forearm is pronated the biceps tendon will be

twisted about halfway around the radius, and contraction

of the biceps will produce supination of the forearm as

well as elbow flexion. However, perhaps due to this wrap-

ping around the radius, the biceps brachii makes only a

minimal contribution to elbow flexion when the forearm is

pronated (Hamill and Knutzen, 1995). Hence, performing a

pull-up with the palms facing away from the body (forearm

pronation) is more difficult than performing a pull-up with

the palms facing the body, and the force generated by

the elbow flexors in a maximal voluntary contraction has

FIGURE 7.41 Biceps brachii and supinator (right arm,

anterior view).