CYBEX VR2 User Manual

The Latissimus Dorsi
• Extension/Adduction - The latissimus dorsi is
responsible for extension as well as adduction
of the shoulder joint. The lat is also 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 motions. The teres major works
alongside the upper fibers of the lat in adduc-
tion and extension. The combined positions of
external rotation to 90 degrees and abduction
to 90 degrees create the most compromising
position for the shoulder joint.
• Range of Motion - Full normal adduction or
extension begins with the arm in a vertical
position overhead at 180 degrees and ends
with the arm at the side in 0 degrees. As the
arm moves from overhead the direction of
travel arcs outward (for adduction) or forward
(for extension) away from the head, then
down, and finally, inward toward the side. Full
concentric shortening of the lat can only occur when the associated scapular motion is per
formed with shoulder motion. With motion and resistance from overhead, scapular depres-
sion is required. For the arm to return to the starting position overhead the eccentric action
of the lat must be accompanied by the scapular rotation of scapulohumeral rhythm.
• Associated Muscles - The lower fibers of the trapezius are responsible for scapular
depression. Slight retraction is always associated with scapular depression as the lower
fibers of the trapezius angle downward and toward midline, attaching on the spine. The long
head of the triceps is involved in shoulder extension and adduction, although change in its
length is limited when elbow flexion coincides with shoulder motion. The biceps,
brachioradialis, and brachialis are always involved in pulling movements as elbow flexion is
required. The degree of their individual involvement depends upon radioulner joint position.
MUSCLES TRAINED
CYBEX VR2 Owner’s Manual
The Positioning
• Adjust the thigh pad to allow access and stabilize the body.
• Check the weight to insure that the appropriate resistance has been selected. Body position
and control of the motion should never be compromised by excessive weight.
Exercise
Page 3-38

CYBEX VR2 Specifications

General

Category	Fitness Equipment
Frame Material	Steel
Weight Stack	Varies by model
Dimensions	Varies by model
Weight Capacity	Varies by model
Color Options	Varies by model
Warranty	Varies by model
Adjustability	Yes