CYBEX VR2 - 10 To 305 Pounds by Fives; Modified Plane Adduction; Scapular Retraction

The Chest
• Modified Plane Adduction - The clavicular
fibers, as well as the upper sternal fibers, of the
pectoralis major are primarily responsible for
adduction of the shoulder through a plane
angled approximately 30 degrees above the
horizontal plane of the shoulder joint. The pec-
toralis major is also involved in flexion and
extension of the shoulder joint, although the
anterior deltoid and latissimus dorsi muscles,
respectively, are mechanically more effective at
performing those motions. The pectoralis major
is involved in internal rotation of the shoulder,
however, this is a mechanically weak motion
and becomes the limiting factor in strength
when combined with other shoulder motions.
• Scapular Retraction - The position of full
scapular retraction, when maintained, creates
the greatest possible force angles of the pec
throughout the range of motion.
• Range of Motion - With scapular retraction maintained, horizontal adduction is limited to
approximately 90 degrees (arm straight to the front) and horizontal abduction (achieved
through the eccentric action “lowering of the weight”) is limited by mechanical disadvan-
tage at approximately 0 degrees (upper arm straight out from the shoulder), when pectoralis
work is isolated as the goal.
• Associated Muscles - The anterior deltoid and coracobrachialis are also prime movers for
the motion of horizontal adduction. However, by maintaining motion in the horizontal plane,
scapular retraction, and limited horizontal abduction (limited stretch) the pectoralis major
will be emphasized over the anterior deltoid. The triceps are always involved in pressing
movements as elbow extension is required.
MUSCLES TRAINED
CYBEX VR2 Owner’s Manual
• 10 to 305 Pounds by Fives - The top plate provides a minimum weight of ten pounds.
Subsequent plates in the weight stack are twenty pounds each. Three “slide-on” five pound
incremental plates are securely positioned for easy access and effortless addition thereby
providing 10 to 305 pounds in five pound increments.
Exercise
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