Download Circumduction and Elevation

Shoulder Circumduction and Elevation
Circumduction can be defined as a conical movement of an appendicular limb, extending
from the joint at which the movement is controlled. True circumduction allows for 360
degrees of movement. Only the ball-and-socket joints — those found at the hip and
shoulder — are truly capable of circumduction, or 360 degrees of movement.
The mechanism at the ball-and-socket, or spheroid, joint that allows circumduction is the
shape of the bones in the joint. On the top of the bone in the attaching limb is the head, a
ball-shaped structure that inserts into a round cavity or socket on the bone receiving the
limb.
Shoulder circumduction is achieved by initially holding a medially extended arm outwards
from the body in the lateral plane, with the elbow joint extended. The movement is
initiated by both abduction and medial rotation of the shoulder. Once at the apex of the
circular path of motion, the limb is then adducted and medially rotated, initiating the
circular movement traced in the air by the phalanges. The action is completed once a full
360 degrees of movement has been completed.
As circumduction is a combination movement, entailing rotation, extension and flexion and
adduction and abduction, all muscles of the shoulder girdle are utilized. We will categorize
the movements into the respective quadrants of movement.
1
3
2
4
Medial View of Right Shoulder
Circumduction
Quadrant
1
Movements
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2
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3
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Medial Rotation
Horizontal
Abduction
Flexion
Lateral Rotation
Horizontal
Adduction
Extension
Lateral Rotation
Horizontal
Agonistic Muscles
Antagonistic Muscles
Pectoralis Major
Rotator Cuff
Synergistic
Muscles
Latissimus Dorsi
(Anterior Deltoid)
Latissimus Dorsi
Rotator Cuff
Pectoralis Major
(Posterior Deltoid)
Deltoid
Trapezius
Deltoid
Trapezius
Rotator Cuff
Latissimus Dorsi
Pectoralis Major
Deltoid
Trapezius
4
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Adduction
Extension
Medial Rotation
Horizontal
Abduction
Flexion
Deltoid
Trapezius
Rotator Cuff
Pectoralis Major
Latissimus Dorsi
Elevation and depression
Elevation of the shoulder girdle can be exemplified through the action of shrugging the
shoulders, whilst depression is the antagonistic movement of elevation.
The muscles involved in elevating the shoulder girdle are the upper fibers of trapezius,
levator scapulae, rhomboid major and rhomboid minor.
The muscles that depress your shoulder blades are the lower trapezius , and your pectoralis
minor in your chest. The agonistic muscles involved in elevation act as antagonistic muscles
in depression of the shoulder, and vice versa.