Dance Anatomy & Kinesiology

390 Dance Anatomy and Kinesiology

Attachments and Primary Actions of Latissimus Dorsi

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

Latissimus dorsi

(lah-TIS-i-mus DOR-see)

T6-L5 spinous processes

Sacrum

Crest of ilium

Posterior aspect of lower

3 ribs

Lower intertubercular

groove of humerus parallel

to attachment of pectoralis

major

Shoulder extension

Shoulder adduction

Shoulder horizontal abduction

Shoulder internal rotation

Depression of humerus

Latissimus Dorsi

The name of this muscle describes both its shape

and location (latissimus, widest + dorsi, back), and

it is the broadest muscle of the back and lateral

thorax. The latissimus dorsi is located superficially,

except where its upper portion is overlapped by the

lower fibers of the trapezius, and laterally it helps

form the back wall of the armpit (axilla). This very

extensive muscle’s proximal attachments include

the lower spine, pelvis, and associated fascia

(lumbodorsal fascia) as seen in figure 7.16. It runs

upward and outward and then forward. Similarly to

the pectoralis major, it twists 180° before attaching

with a flat tendon to the anterior humerus, parallel

to the attachment of the pectoralis major. Due to

this anterior attachment it tends to produce shoulder

internal rotation, as well as being a powerful exten-

sor of the shoulder used in resisted “downward

and backward pulling” motions of the arms, as in

swimming, rowing, rope climbing, and pull-ups. When

used in conjunction with the pectoralis major, the

latissimus dorsi is also a powerful adductor of the

arm (Hall-Craggs, 1985).

Due to its extensive bony and fascial attach-

ments, the latissimus dorsi also serves an important

function in stabilizing the trunk; and when the arms

are fixed (closed kinematic chain movement), the

distal attachment of the latissimus dorsi can aid with

lifting the pelvis as in crutch walking, sitting push-

ups, or dance floor work. Posturally, the latissimus

dorsi can aid with depression of the humerus, and

this function is sometimes emphasized in dance.

Loss of the latissimus dorsi is associated with forward displacement of the shoulder and loss of strength

in downward movements of the arm against resistance.

Palpation: Place your left hand on a stationary object such as a desk, with the elbows slightly bent

and the fingertips of your right hand about 8 inches (20 centimeters) below the back portion of your

left armpit on your posterolateral rib cage. You can feel the latissimus dorsi contracting under your right

hand when you press down firmly with your left hand (isometric shoulder extension).

Teres Major

The teres major (teres, round + major, larger) is similar in shape to the teres minor, only larger, hence

its name teres “major.” It runs from the lateral border of the lower scapula outward and upward to

attach onto the anterior humerus (figure 7.16). When resistance must be overcome, the teres major

comes into play and has the same actions as the latissimus major. Hence, it is sometimes called “the

latissimus dorsi’s little helper” (Rasch and Burke, 1978). When the arm is behind the back, the teres

FIGURE 7.16 Posterior view of superficial shoulder

muscles: latissimus dorsi, teres major, and deltoid (left

shoulder).