374 Dance Anatomy and Kinesiology
T
he upper extremities, which include the shoul-
der girdle, arms, and hands, are the focus of
this chapter. The arms are intimately connected with
movements of the shoulder girdle, and hence the
shoulder girdle and shoulder joint should be viewed
together as a functional unit. The shoulder girdle
and shoulder joint are characterized by a design
that maximizes mobility necessary for reaching,
grasping, lifting, and throwing. Such mobility makes
specific muscle strength development and activation
important for correct technique and injury preven-
tion. In dance, very specific and subtle use of the
arms is often required to meet the aesthetics of the
school of dance or a given choreographer. In some
cases, stylized use of the arms is vital to portray the
desired emotional quality of the dance movement.
Furthermore, with partnering, the arms often come
into play to help support a partner, as well as help
express a relationship between the dancers as shown
in the photo on the previous page.
The upper extremity will be covered all together
in this chapter. While some sports such as throwing
sports, swimming, weightlifting, and gymnastics place
great stress on the upper extremity, dance tends to
place greater stress on the lower extremity. Hence,
the upper extremity is not covered in as much detail
in this text as the lower extremity, and the emphasis
is on the shoulder joint. Topics covered will include
the following:- Bones and bony landmarks of the shoulder com-
plex - Joint structure and movements of the shoulder
girdle - Joint structure and movements of the shoulder
- Description and functions of individual muscles
of the shoulder complex - Alignment and common deviations of the shoul-
der complex - Shoulder mechanics
- Muscular analysis of fundamental shoulder move-
ments - Special considerations for the shoulder complex
in dance - Other joints of the upper extremity
- Description and functions of selected individual
muscles of the elbow - Structure and movements of the radioulnar
joints - Key considerations for the upper extremity in
whole body movement- Conditioning exercises for the upper extremity
- Upper extremity injuries in dancers
Bones and Bony Landmarks of the Shoulder Complex
The shoulder complex involves the clavicle (col-
larbone), scapula (shoulder blade), and humerus
(upper arm bone) on each side of the body.
When seen from above, the clavicle is shaped like
a stretched-out āSā that is convex anteriorly in its
medial portion and concave anteriorly in its lateral
portion (figure 7.1). The medial end (sternal end) of
the clavicle is slightly expanded, while the lateral end
(acromial end) is markedly expanded and flattened;
these shapes aid in articulation with the respective
adjacent bones.
The scapula is a large, triangular-shaped flat bone
that normally glides on the posterior rib cage. This
bone has many muscles attached to it, and many dif-
ferent bony landmarks are used to clarify the sites
of attachment of these muscles. As can be seen in
figure 7.2, the scapula has three borders, the medial
(vertebral), lateral (axillary), and superior borders,
as well as three angles (the superior, inferior, and
lateral angles). It also has two surfaces; the anterior
surface, which lies close to the ribs, is termed the
costal surface, while the posterior surface is termed
the dorsal surface. The costal surface is slightly
hollowed to form the subscapular fossa. The dorsal
surface is divided by a large spine, into a smaller
but deeper hollowed area above the spine called
the supraspinous fossa and a larger but shallower
infraspinous fossa below the spine. The spine of
the scapula ends laterally in a large flattened process
called the acromion process (G. akron, tip + omos,
shoulder). This process articulates with the clavicle
to form the acromioclavicular joint. The lateralFIGURE 7.1 The clavicle (right clavicle, superior view).