Dance Anatomy & Kinesiology

382 Dance Anatomy and Kinesiology

scapula, forming a force couple (chapter 2) whereby the lower portion of the trapezius pulls down on

the medial border of the scapula as the upper portion of the trapezius pulls up on the acromion. The

combined action is to produce rotation in the same direction, that is, upward rotation of the scapula.

Upward rotation of the scapula accompanies elevation of the arm, and so the trapezius works when-

ever the arm is raised to the side (shoulder abduction) and in higher ranges of raising the arm to the

front (shoulder flexion). The lower portion of the trapezius also tends to depress the scapula, and this

function is often emphasized in dance training. In contrast, the upper portion of the trapezius tends

to elevate the scapula (as when you shrug your shoulders) and provides support for the distal end of

the clavicle and acromion process of the scapula. This latter function comes into play when a heavy

weight, such as a suitcase, is held in the hand (Hamilton and Luttgens, 2002). In such cases, tension

and often fatigue or soreness are experienced in the upper trapezius. This latter lateral support function

may also affect shoulder posture, in that weakness of the trapezius can result in a lower and forward

position of the point of the affected shoulder consequent to the downward rotation of the scapula from

the weight of the hanging arm and abduction of the scapula (Smith, Weiss, and Lehmkuhl, 1996). When

the head is free to move, the upper trapezius can assist with extension, lateral flexion, and rotation (to

the opposite side) of the cervical spine.

Palpation: Place the fingertips of your left hand just behind the outer third of the right clavicle with

your right arm held overhead. You can feel the upper trapezius contracting when you bring your right

shoulder up toward your ear (scapular elevation) in this position. On a partner, you can palpate the

lower portion of the trapezius contracting medial to the inferior angle of the scapula when your partner

actively pulls his or her shoulder blades together and down (scapular depression and adduction). You

can see and feel the entire muscle contracting when your partner pulls the shoulder blades together

with the elbows just above shoulder height (scapular adduction).

Levator Scapulae

The levator scapulae (L. levator, a lifter) is a small muscle

that lies beneath the upper trapezius and extends from the

upper cervical vertebrae to the upper medial border of the

scapula (figure 7.9). Hence, its line of pull is almost verti-

cal, with a slight lateral progression as it runs inferiorly.

Thus, its primary action is elevation of the scapula with the

ability to contribute slightly to scapular adduction. During

standing, due to the weight of the arm pulling downward

on the glenoid cavity, contraction of the levator scapulae

also tends to produce downward rotation of the scapula

(Rasch and Burke, 1978; Smith, Weiss, and Lehmkuhl,

1996). Loss of the levator scapulae is associated with the

shoulder’s being depressed, especially when the trapezius

is also not functioning adequately. Loss of both of these

muscles is associated with a marked slope of the shoul-

ders and a thin neck. When the head is free to move, the

levator scapulae can produce lateral flexion and rotation

(to the same side) of the cervical spine.

Palpation: Because the levator scapulae lies beneath

the trapezius and commonly works in conjunction with the

trapezius, it is difficult to palpate in isolation.

Attachments and Primary Actions of Levator Scapulae

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

Levator scapulae

(le-VA-tor SKAP-u-le)

C1 to C4 or C5 transverse

processes (from spine to

superior border)

Medial border of scapulae Scapular elevation

Scapular downward rotation

Assists with scapular adduction

FIGURE 7.9 Deep posterior scapular muscles: levator

scapulae and rhomboids (left scapula).