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Here you will find an article on one exercise
(new one every month). With a detailed analysis of the
muscles used during the exercise and a informative description
of how to both perform and assist in the actual performance
of the exercise.
A full library of all previous exercises
can be found at members online under the sub menu
Exercise:
Dumbbell Lateral Raise
Client Instruction:
Starting Position
1. Stand in an upright position with your feet shoulder
distance apart and your knees slightly bent
2. Hold a dumbbell in each hand with a neutral grip in
front of your body with your palms facing each other and
your elbows slightly bent.
3. Tighten your abdominals to support your low back and
keep your elbows in a slightly flexed position throughout
the exercise
Up Phase
4. From this starting position, inhale and begin to raise
the dumbbells directly sideways.
5. Continue to raise the dumbbells away from your body
to a final position at approximately shoulder height
Down Phase
6. Pause and then slowly lower
the dumbbells back to starting position
7. Repeat the exercise lifting your right shoulder up and
towards your elevated left knee
Muscle Analysis
Chart - Dumbbell Lateral Raise
| Up Phase |
| Joint |
Action |
Contraction |
Muscle Group |
Specific Muscles |
| Shoulder Joint |
Abduction |
Concentric |
Shoulder Joint Abductors |
Deltoid
Supraspinatus |
| Down Phase
** |
| Shoulder Joint |
Adduction |
Eccentric |
Shoulder Joint Abductors |
Deltoid
Supraspinatus |
In the down phase of the exercise the weight is lowered slowly
with gravity. The muscles that concentrically contracted to
lift the weight are the same muscles that are eccentrically
contracting to lower the weight.
General
Kinesiological Analysis
In a dumbbell lateral raise, the supraspinatus
and deltoid contract to cause shoulder joint abduction. The
serratus anterior, trapezius and the pectoralis minor contract
to move the scapula into abduction and upward rotation. The
biceps brachii, brachialis, brachioradialis and the pronator
teres contract statically to hold the elbow joint in slight
flexion.
Advanced Kinesiological
Analysis
The supraspinatus and the deltoid are prime movers in shoulder
joint abduction. The serratus anterior, trapezius and the
pectoralis minor are the prime movers in abduction and upward
rotation of the scapula. The dumbbell lateral raise is a variation
of the shoulder press and the upright row, when the shoulder
joint is examined. All three exercises cause abduction of
the shoulder joint. However, in each of these exercises there
is a differing degree of rotation of the humerus during their
range of motion. In the upright row, the humerus is medially
rotated before the shoulder joint is abducted by the supraspinatus
and the posterior deltoid.
In the shoulder press, the humerus is laterally rotated before
abduction of the shoulder to allow the supraspinatus and the
anterior deltoid to contract. In the dumbbell lateral raise,
the shoulder joint is at a midpoint position between the medial
rotation of the upright row and lateral rotation of the shoulder
press. At this position, the supraspinatus continues to contribute
to the contraction, while the three heads of the deltoid contribute,
with a greater emphasis on the middle head. The middle portion
of the deltoid is the most powerful of all the heads with
its greatest activity reported between 80-110 degrees of abduction.
When all heads of the deltoid contract, there is a strong
stabilizing force that pulls the head of the humerus into
the glenoid cavity. The deltoid’s multi-pennate form
assists with this strong stabilization force.
In all movements of the shoulder joint, the scapula must
also move at some point within the range of motion. The main
function of the scapula movements is to increase the range
of motion of the humerus during shoulder joint movements.
In the shoulder press, upright row and the dumbbell lateral
raise the movements of the scapula assist in the movement
by abduction and upward rotation.
Due to the differences in humeral rotation at the beginning
of the exercises, there are distinct differences in how the
scapula reacts. In an upright row the humerus is medially
rotated before shoulder joint abduction causing the scapula
to move into abduction much later than the dumbbell lateral
raise and the shoulder press. In the dumbbell lateral raise,
the humerus, while in its mid medial–lateral rotation
engages the outer flared portion of the scapula much earlier,
forcing the scapula to abduct earlier in the movement. In
the shoulder press, the humerus is in a lateral rotation,
which partially disengages the tip of the humerus with the
flared part of the scapula. The scapula begins to move at
a position that is midway between the upright row and the
dumbbell lateral raise.
Cable Pulley Variations
A variation of the dumbbell lateral raise is a low cable
lateral raise. The client grasps the handle of the low cable
pulley machine after positioning the opposite side of the
body facing the weight stack. The client supports the body
by placing the furthest foot from the weight stack in front
of the other foot and pulls the handles away from the weight
stack. The actions and the muscles at the shoulder joint and
the scapula are the same as the dumbbell lateral raise. One
advantage in using the cable lateral raise is the variation
in starting positions that is possible. By positioning the
body slightly away from the weight stack, it is possible to
place the middle deltoid on a greater pre stretch prior to
the contraction.
Stability Ball Variations
The client kneels on a stability ball with a dumbbell in
each hand. While maintaining balance on the stability ball
the client abducts the shoulders in a lateral raise action
with the elbows held in slight static flexion. The dumbbells
are raised to a position slightly higher than shoulder height
and then slowly lowered back to the starting position. This
exercise can also be performed from a sitting position.
Disclaimer: No responsibility is accepted for any loss
or damage suffered as a result of the use of the above
information
or any reliance on it. Users should satisfy themselves
as to their own or clients medical and physical condition
before adopting/using
the information or recommendations made. No responsibility
or liability is accepted for any loss or damage suffered
by any person as a result of adopting the above information
or recommendations.
Further information
1300 136 632 Phone +61 02 9212 7185 or Fax +61 02 9211
0002
Suite 505/410 Elizabeth Street Surry Hills 2010 Sydney
Australia
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