The video will begin our review of the muscles of the upper extremity.
We will start off with the deltoid, the biceps brachii, the brachialis and the triceps brachii.
To begin with the deltoid, the proximal attachments differ based on which exact fibers you're
talking about.
The anterior fibers have their proximal attachment along the lateral 3rd of the clavicle.
The lateral fibers have their attachment along the lateral border of the arcomion process.
And the posterior fibers have their attachment along the spine of the scapula.
Together these 3 fibers come to distally attach at the deltoid tuberosity of the humerus.
As the deltoid muscle shortens it is responsible for abduction of the arm but only after the
1st 15 degrees.
The supraspinatus muscle is responsible for the 1st 15 degrees and we'll cover this in
the next video.
The different fibers of the deltoid also have slightly different actions.
The anterior fibers because of their position on the anterior side of the body, also assist
with flexion of the arm at the shoulder, as well as medial rotation of the arm.
The posterior fibers because of their location on the posterior side assist with extension
of the arm at the shoulder as well as lateral rotation.
You can see these actions taking place as shortening of the muscle is demonstrated.
The biceps brachii has its short head proximally attaching at the coracoid process of the scapula
and it's long head proximally attaching at the supraglenoid tubercle which is right there.
The 2 heads come together via a single tendon to distally attach at the radial tuberosity
of the radius.
As you can see, shortening of this muscle would cause flexion of the forearm.
Additionally, shortening of the muscle would cause supination at the radioulnar joint which
looks like this.
Finally, the biceps is also responsible for very weak flexion of the arm.
Because the biceps muscle crosses over 3 joints with the long head traversing over the shoulder
joint and both heads crossing the elbow joint as well as the radioulnar joint, this muscle
has 3 different actions.
The brachiallis muscle proximally attaches at the mid shaft of the humerus and distally
attaches at the coronoid process of the ulna, which is right here.
When this muscle shortens it is responsible for flexion of the forearm at the elbow.
Each head of the triceps brachii has its proximal attachment at a different site.
The lateral head of the triceps has its proximal attachment along the upper half of the posterior
surface of the humoral shaft.
Along here.
The medial head has its proximal attachment along the posterior surface of the humerus
distal to the radial groove.
Right here.
And the long head has its proximal attachment at the infraglenoid tubercle of the scapula.
Right Here.
Together these three heads come together to attach at the olecranon process of the ulna.
Right here.
The triceps is largely responsible for extension of the forearm at the elbow.
You can see this happening as we move from a flexed position to an extended position.
It is also responsible because the long head has a proximal attachment that is proximal
to the shoulder joint.
It is able to enact some action at this joint as well.
Namely, extension of the arm at the shoulder as well as some amount of adduction of the
arm.
The next series of poses will work into the
deltoid muscle.
With the inhale you can let the arms lift up and over the head.
And on the exhale you can hinge at the hips and fold forward, reaching down towards the
ground.
Inhale lift up halfway hands on the knees, shoulder pulling back.
And on the exhale plant the hands on the mat and step your way to a high plank.
Go ahead and drop your elbows down onto the earth finding your way into a forearm plank
taking care to align to make sure that the wrists and elbows are in the same line and
that the hands are pressing flat into the earth.
Pushing down deep into the fingertips.
To make your way into dolphin pose on the next exhale, tip toe your feet forward so
the hips start to pike up towards the sky much like a downward facing dog.
This is Dolphin pose.
You'll notice that the arms are flexed here and they are isometrically medially rotating
as the deltoid muscle engages in order to maintain the pose.
You can hold here through the inhale and notice the work being done by the anterior fibers
of the deltoid muscle with the next exhale let the knees drop down towards the ground
and come to a seated position letting the hips sink back onto the heels and then letting
the feet extend out in front of you.
Go ahead and put a bend in the knees, planting the soles of the feet on the earth and then
planting the hands about 6 inches behind you.
On the next inhale let the hips lift up toward the sky, finding your way into an inverse
table pose spreading the feet apart about a hip width distance, trying to bring the
hips so they're in line with the ground.
Taking care to roll the shoulders back.
Noticing that in this pose you have extension and lateral rotation at the shoulders.
Which are both actions that the posterior fibers of the deltoid muscle are responsible
for.
On the exhale you can lower your hips down halfway towards the earth, gently releasing
from the pose and then inhale them back up noticing the engagement along the posterior
aspect of the deltoid.
Exhale lower down.
Inhale lift back up.
One last time exhale lower the hips down and inhale lift them back up.
With the next exhale you can lower them down all the way to the ground, releasing the pose,
walking the hands back closer to the hips and letting the feet extend back out in front
of you.
Our next few poses will engage the biceps, brachiallis and triceps muscles.
With the next inhale, let the arms lift up and over the body, and on the exhale hinge
from the hips reaching towards the toes, the feet or the ankles.
If your reaching for the toes you can use the index and middle finger to bind the big
toes, if your reaching for the ankles try to have a really firm grip around the ankles.
With the inhale, lengthen through the spine, letting the gaze pull forward and with the
exhale flex the forearms as you pull the upper body down closer to the legs.
With each inhale find length creating more space in the spine and with each exhale flex
deeper to help you pull the upper body closer to the legs.
Holding once you find a place that feels comfortable for you, maybe noticing even- how the supination
that you have at the forearms, noticing that the inner aspects of the forearms turn upwards
slightly helps deepen the engagement that you have of the biceps muscle.
With the next breath in you can lengthen.
And on the exhale you can walk the hands back along the legs.
Coming back to your neutral seated position.
Next placing the hands about 6 inches behind the hips, using the next inhale to roll the
shoulders back and with the exhale letting the hips lift up the sky, letting the toes
point down towards the ground, pointing up or facing plank.
Use the inhale to roll the shoulders back and each exhale to lift the hips just a little
bit higher noticing the engagement you have in your triceps muscles here.
You have the forearms extended and extension at the shoulder as well.
These are both actions that are generated by the triceps muscle and you can feel it
working hard to hold you steady in this pose here.
Continue to breathe through the pose.
With the next inhale lifting, lengthening a little bit higher.
And exhale setting the hips back down onto the ground.
Walking the hands back to their neutral position.