Download anatomy of the shoulder

ANATOMY OF THE SHOULDER
Before learning Thai Yoga Stretching postures for the upper body, we will review some
of the anatomical structures in the shoulder joint. In reviewing these key bones and
muscles, we will have a deeper level of understanding of how to use our Thai Yoga
techniques to ease our clients into more optimal ranges of flexibility and mobility.
Major Bones of the Shoulder Girdle
Scapula –
Otherwise called the shoulder blade, the scapula is what allows us such a large range
of motion in the shoulder. The arm connects to the rest of the skeleton through the
scapula.
Clavicle –
Also known as the collarbone, the clavicle connects the scapula to the rest of the
skeletal structure.
Humerus –
The upper arm bone that connects with the scapula at the glenohumeral joint.
clavicle
scapula
humerus
Daniela Goode | Specialty Training
[email protected] | 1.855.607.9642 | www.navina.ca
Joints of focus in the shoulder girdle:
Glenohumeral joint –
Where the humerus and the scapula connect. The “gleno” part of
the name refers to the structure on the scapula known as the glenoid
fossa, where the head of the humerus connects, to form the joint.
Sternoclavicular joint Articulation point of the clavicle and the sternum (centre of chest).
Acromioclavicular joint –
Commonly referred to as the “AC joint”, this is where the clavicle meets the scapula.
The “acromio” portion of the name refers to the structure of the scapula known as the
Acromion process.
Major muscles of the shoulder
Although there are numerous muscles that act on the
joints of the shoulder, we will narrow our focus to a few
of the major players – the prime movers in many
shoulder movements.
Trapezius –
One end of this large muscle connects to the spine and
skull all the way from the occipital lobe down to the
lower thoracic vertebrae. The distal end of the muscle
inserts into the spine of the scapula and wraps over the
top of the shoulder to connect with the clavicle as well.
The trapezius is divided into 3 portions: Upper, Middle,
and Lower, and has the following main actions:
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Upper Fibres: elevation and upward rotation of the scapula
Middle Fibres: adduction (retraction) of the scapula
Lower Fibres: depression and upward rotation of the scapula
Daniela Goode | Specialty Training
[email protected] | 1.855.607.9642 | www.navina.ca
Levator scapulae –
This muscle connects the upper cervical vertebrae to the
medial, superior border of the scapula. As its name suggests, the
primary action of the levator scapulae is to elevate the scapula.
Latissimus dorsi –
You may be wondering why this muscle is included in the shoulder
section when it’s clearly located in the mid- lower back. The reason for
this is because sometimes we are more concerned with the action of
the muscle than it’s location (this is one of those times). Otherwise
known as the lats, this large muscle attaches at the spine from the
mid-thoracic region to the lumber spine and inserts into the anterior
aspect of the humerus.
Because it attaches to the humerus, the joint actions of latissimus dorsi
include movements in the shoulder joint, such as: adduction, extension
and internal rotation of the shoulder.
Pectoralis Major –
Commonly called the ‘pecs’ this muscle originates at
the sternum and the inferior border of the clavicle, and
inserts into the lateral aspect of the humerus.
Key actions of the pectoralis major include: flexion,
horizontal adduction and internal rotation at the
shoulder joint.
Daniela Goode | Specialty Training
[email protected] | 1.855.607.9642 | www.navina.ca
Deltoids –
Can be separated into 3 different sections (anterior, lateral,
and posterior) that all produce different actions when
activated separately. They originate at different loci,
beginning from the spine of the scapula, traveling along the
border of the acromion and connecting at the clavicle as
well. All divisions insert into the lateral aspect of the humerus.
The main actions of the deltoids are:
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Anterior: flexion of the shoulder
Lateral: abduction of the shoulder
Posterior: extension of the shoulder
Now that we’ve reviewed key anatomical structures in the shoulder girdle, we can
apply this knowledge to our next Thai Yoga Stretching posture.
Daniela Goode | Specialty Training
[email protected] | 1.855.607.9642 | www.navina.ca
LUBRICATING THE SHOULDER
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Stance: Warrior
Rock: n/a
Touch: n/a
What’s our aim for this pose? What are the
benefits?
Lubricating the Shoulder is meant to warm up
and lightly stretch the muscles of the shoulder
girdle, including all of the deltoids, the pectorals and the latissimus dorsi. While the
trapezius and levator scapulae are not the focus of the stretching, both will also benefit
from learning how to relax and allow the movement to be passively generated.
Whenever facilitating the movement of a joint through its full range of motion we help
to trigger the production of synovial fluid, hence the lubricating effect of this pose.
Circumduction of the shoulder in this way is also a great exercise in building trust on the
behalf of the receiver.
Extra tips and notes:
It is important to know that many people will be unable to fully release into this posture
and give you complete control over their shoulder motion. For many reasons this tends
to be an area of the body that we subconsciously protect. If you find that your client is
not fully relaxing into the passive nature of this movement, it is sometimes helpful to give
their upper arm a gentle shake to help stimulate a relaxation effect.
In some cases this posture may be contraindicated; for example when there is a history
of recent (or recurrent) shoulder dislocation. In this instance, you would generally avoid
Lubricating the Shoulder.
All shoulders will be different and some will click or crack when taken to the edge of
their range of motion. Often this will be fine, but it is a good idea to have verbal
dialogue when this happens to make sure your client is still comfortable.
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Daniela Goode | Specialty Training
[email protected] | 1.855.607.9642 | www.navina.ca