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Unilateral Incline Dumbbell Raises For Peak Shoulder Performance |
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Written by Stephen E. Alway, PhD, FACSM
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Monday, 23 April 2007 |
Training is, of course, one way to minimize the potential for shoulder
injury. Occasionally, aggressive shoulder training has its place as a
preparative program for shoulder performance. However, this must be
tempered with a variety of exercises and training volumes, and it must
also be distinctly different from sloppy training couched in the name
of intensity. Whatever your application, peak shoulder performance
requires maximal strength and flexibility and a complete balance of the
forces and torques generated around and through the shoulder joint. The
trick is to optimize your shoulder's ability to produce and absorb
forces without inducing injury that will keep you out of competition.
Muscle Structure and Function
The deltoid is a superficial muscle that overlays the other muscles
working at the shoulder. It has three functionally distinct parts. The
anterior fibers from the deltoid muscle begin along the lateral part of
the clavicle (collarbone). They attach to the deltoid tuberosity, a
bumpy area on the upper part of the humerus bone of the upper arm. The
anterior deltoid acts to raise the arm in front of your body (shoulder
flexion). It's also activated in pushing movements that require
shoulder flexion. This region of the deltoid also helps medially rotate
the arm at the shoulder joint by turning the humerus bone inwards.
The posterior fibers of the deltoid begin along the spine of the
scapula (shoulder blade) near the shoulder. These fibers also attach to
the humerus bone at the deltoid tuberosity. When the posterior fibers
of the deltoid contract, they pull the humerus bone backward
(posteriorly) into shoulder extension. The medial fibers of the deltoid
begin on the middle part of the acromion, a lateral part of the bony
scapula that forms the "point" of the shoulder. The fibers from the
medial deltoid all converge on the deltoid tuberosity on the humerus
bone. Contraction of the medial fibers of the deltoid abducts the arm
by raising it out to the side of the body (i.e., moving it away from
your torso). This is the movement used for lateral dumbbell raises.
The supraspinatus muscle of the rotator cuff contracts at the same time
the medial fibers of the deltoid are active, and both act to abduct the
arm. However, the supraspinatus and medial deltoid muscle fibers can
only raise the arm to a position that's about parallel to the ground.
Therefore, if you raise your arms further than this, you're not
activating the deltoid any more completely. Rather, you're stimulating
the serratus anterior and trapezius muscles that must work in concert
to rotate the scapula and move the shoulder joint into a higher
position. We will exploit this anatomical feature in one-arm
(unilateral) incline dumbbell raises, to maximize the activation of the
medial part of the deltoid, strengthen the supraspinatus and minimize
the trapezius muscle involvement in the exercise.
Unilateral Incline Lateral Raise
The unilateral incline lateral raise is a specialized version of the
more conventional lateral dumbbell raises. Normally, if you were to do
standing dumbbell lateral raises, the resistance does not become very
intense until you have raised (abducted) your arms about 30 degrees
from the starting position. This is because your shoulders have a
strong lever arm in the standing version, so the resistance feels light
at the beginning of the lift. The resistance feels much heavier near
the top of the lift at the weakest part of your strength curve, but
it's this point that limits the resistance you can lift in lateral
raises. The incline bench reduces the length of the lever arm and
therefore the resistance becomes much more effective from the beginning
of the lift. This improves the overall quality of each repetition.
1. This exercise should be performed sitting on a 30 to 45-degree
incline bench. You can do this exercise with both hands working
simultaneously, but it will be described here using one arm at a time.
Either pick a dumbbell from off the floor beside your bench, or have
your training partner hand you the dumbbell. Use your non-working hand
to hold onto the edge of the incline bench for additional support and
stability.
2. The hand holding the dumbbell should be hanging vertically toward
your body. The dumbbell should be turned so your palm faces toward your
torso. Your elbow should be just short of straight, but the elbow joint
angle should not change throughout the range of motion.
3. The tendon to the supraspinatus muscle is vulnerable to
stretching-induced injuries at the beginning of the movement, so it's
important not to jerk the weight upward. Instead, make this a smooth,
forceful, but not ballistic effort to lift the dumbbell (i.e.,
abduction of the arm at the shoulder joint). Move the dumbbell to a
position that's only slightly above shoulder level. Hold this top
position for a count of two so the deltoid contracts isometrically.
4. Slowly lower the dumbbell halfway to the starting position, then
stop and return to the top position. Again, hold this for a count of
two, then finally lower the weight back to the starting position to
complete your first repetition.
5. If you don't have any rotator cuff problems, you can add a medial
rotation to the lift. This will further stimulate your shoulder growth.
As the top position is approached, rotate your shoulder so the knuckle
of the little finger is pointing upward and your thumb is downward.
This medial rotation of the humerus will bring the anterolateral region
of the deltoid into play (fibers between the lateral and anterior
regions) and thereby thicken the tie-in between these two regions of
the deltoid.
6. As you begin to lower the weight and then return the dumbbell slowly
to the starting position, slowly rotate your shoulders laterally and
this will result in a slight supination of your hands. (Do not actually
attempt to supinate your hands; but let the shoulder rotation do this
for you).
You Should Know...
The medial fibers of the deltoid will be isolated in this exercise as
few other exercises can. However, there is potential involvement from
the trapezius and anterior serratus muscles if you raise the dumbbell
too high. The preferred starting position is adjacent to the lateral
portion of the thighs, as opposed to the anterior (front) of the thigh.
If any adjustment is to be made to the starting position, it's better
to begin with the dumbbell behind the plane of your back, not further
to the front.
Make sure that when the knuckle of your little finger is pointing
upward, this "twist" will be produced by a rotation at the shoulder,
not at the wrist. Twisting the wrist at the top will only give you sore
wrists, not large deltoids. Completion of each half repetition at the
top of the lift and between the full repetitions will send a small
brush fire-like pain into your medial deltoid. However, this will soon
be a three-alarm adventure by the fifth repetition of the first set.
Still, this additional activation will be just the thing to wake
dormant fibers in the medial deltoid muscle.
The shoulder is a very unstable joint and prone to injury, and
therefore it makes sense to explore alternatives to using superhuman
weights for developing shoulder mass. Adding the half repetitions and
medial rotation accomplishes these goals by magnifying the intensity of
each contraction without requiring staggering weights. To further
maximize the efforts for each contraction, avoid relaxing your muscles
between repetitions. Instead, immediately after reaching the starting
position, begin the next repetition upward, thereby attempting to
maintain tension in the medial deltoid fibers during the entire set.
With good training habits and effective exercises, you'll not only
possess those thickly erupting fibers of the medial deltoid, but your
shoulder girdle will stay healthy and free of injury.
References
Friden, J., Lieber, R.L., 2001. Quantitative evaluation of the
posterior deltoid to triceps tendon transfer based on muscle
architectural properties. J.Hand Surg.[Am.] 26, 147-155.
Gagey, O., Hue, E., 2000. Mechanics of the deltoid muscle. A new approach. Clin.Orthop., 250-257.
Halder, A.M., Zhao, K.D., Odriscoll, S.W., Morrey, B.F., An, K.N.,
2001. Dynamic contributions to superior shoulder stability.
J.Orthop.Res. 19, 206-212.
Lorne, E., Gagey, O., Quillard, J., Hue, E., Gagey, N., 2001. The
fibrous frame of the deltoid muscle. Its functional and surgical
relevance. Clin.Orthop., 222-225.
Reddy, A.S., Mohr, K.J., Pink, M.M., Jobe, F.W., 2000.
Electromyographic analysis of the deltoid and rotator cuff muscles in
persons with subacromial impingement. J.Shoulder.Elbow.Surg. 9, 519-523.
Roman-Liu, D., Tokarski, T., Kaminska, J., 2001. Assessment of the
musculoskeletal load of the trapezius and deltoid muscles during hand
activity. Int.J.Occup.Saf Ergon. 7, 179-193.
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