© Group 5 | 1 OTA
long, slender bone that lies horizontally across the root of the neck just beneath the skin
articulates with the:
sternum and 1st costal cartilage (medially)
with the acromion process of the scapula (laterally)
acts as a strut that holds the arm away from the trunk
transmits forces from the upper limb to the axial skeleton and provides attachment for muscles
the medial two thirds of the clavicle is convex forward and its lateral third is concave forward.
a flat triangular bone
lies on the posterior chest wall between the 2nd and 7th ribs.
On its posterior surface, the spine of the scapula projects backward.
The lateral end of the spine is free and forms the acromion
The inferior angle of the scapula can be palpated easily in the living subject and marks the level of the 7th rib and the spine of the 7th thoracic vertebra
Parts of the Scapula
articulates with the clavicle
Glenoid Cavity or Fossa
formed by superolateral angle of the scapula
articulates with the head of the humerus at the shoulder joint
projects upward and forward above the glenoid cavity
provides attachment for muscles and ligaments
medial to the base of the coracoid process
formed by the concave anterior surface of the scapula
Supraspinous Fossa (above) & Infraspinous Fossa (below)
divided by the spine at the posterior surface of the scapula
articulates with the scapula at the shoulder joint
articulates with the radius and ulna at the elbow joint
Parts of the Humerus
upper end of the humerus
forms about one third of a sphere and articulates with the glenoid cavity of the scapula.
immediately below the head
separates the lesser tuberosities from each other
where the upper end of the humerus joins the shaft
about halfway down the lateral aspect of the shaft
a roughened elevation
behind and below the tuberosity
accommodates the radial nerve
Medial and Lateral Epicondyles
lower end of the humerus
for the attachment of muscles and ligaments
for articulation with the head of the radius
for articulation with the trochlear notch of the ulna
above the capitulum
receives the head of the radius when the elbow is flexed
above the trochlea anteriorly
receives the coronoid process of the ulna in elbow flexion
above the trochlea posteriorly
receives the olecranon process of the ulna when the elbow joint is extended
made up of muscles and tendons that keep the head of
the humerus in the shoulder socket and helps raise and rotate the arm
|Subscapular fossa||Lesser tuberosity of humerus||Upper and lower subscapular nerve||Medially rotates the arm and stabilizes shoulder joint|
A large triangular shaped muscle that originates from the subscapular fossa
"Subscapularis" means under (sub) the scapula (wingbone)
|Upper two thirds of lateral border of scapula||Greater tuberosity of humerus; capsule of shoulder joint||Axillary nerve||Laterally rotates arm and stabilizes shoulder joint|
narrow, intrinsic muscle
comprises the borders of the two intermuscular spaces of the axilla
Quadrangular space - found below the shoulder joint. The function of this space is to provide passageway for the axillary nerve and posterior circumflex humeral artery, from the anterior to posterior shoulder regions.
Triangular space - located medially to the quadrangular space. This space is traversed by the circumflex scapular artery.
|Lower third of lateral border of scapula||Medial lip of bicipital groove of humerus||Lower subscapular nerve||Medially rotates and adducts arm and stabilizes shoulder joint|
Also known as "lat's little helper" because of its synergy with the latissimus dorsi
The trigger points in this muslce typically refers to the pain in the:
posterior deltoid region and over the long head of the triceps brachii, posterior shoulder joint
occasionally in the dorsal aspect of the forearm
rarely into the scapula or elbow
|Infraspinous fossa of scapula||Greater tuberosity of humerus; capsule of shoulder joint||Suprascapular nerve||Laterally rotates arm and stabilizes shoulder joint|
Infraspinatus is a powerful lateral rotator of the humerus.
Due to the anatomical relation and being separated only by the spine of the scapula, infraspinatus and supraspinatus are considered as one functional unit.
When the arm is abducted, infraspinatus works with teres minor to oppose the upward pull of the deltoid muscle and to stabilize the humeral head against the glenoid fossa. Therefore preventing the upward displacement of the humeral head and the impingement on the coracoid process.
|Supraspinous fossa of scapula||Greater tuberosity of humerus; capsule of shoulder joint||Suprascapular nerve||Abducts arm and stabilizes shoulder joint|
A small muscle of the upper back
A study conducted by Wattanaprakornkul et al. (2011) discovered that the supraspinatus muscle was consistently affected by the prior movements of the limb at all loads, with the use of electromyography to study the levels of activity in the shoulder muscles during flexion
Furthermore, the researchers also stated that the posterior rotator cuff muscles are counterbalancing the anterior translational forces which is produced during flexion and with this, the supraspinatus appears to be one of the muscles that consistently initiates flexion.
|Lateral third of clavicle, acromion, spine of scapula||Middle of lateral surface of shaft of humerus||Axillary nerve||Abducts arm; Anterior fibers internally rotates & flexes arm ; middle fibers abducts arm ; posterior fibers laterally rotates & extends arm|
A large, triangular muscle occupying the upper arm and the shoulder giving it this rounded shape.
It consists of three sets of fibers: anterior, middle, and posterior.
|Second to 5th thoracic spines||Medial border of scapula||Dorsal scapular nerve||Raises medial border of scapula upward and medially|
Is a broad quadrilateral muscle
|Ligamentum nuchae and spines of 7th cervical and 1st thoracic vertebrae||Medial border of scapula||Dorsal scapular nerve||Raises medial border of scapula upward and medially|
Is a cylindrical muscle
The constant postural strain experienced by the rhomboid muscles can lead to their dysfunction and can limit the superior rotation of the scapula and glenoid cavity, which may lead to poor shoulder mechanics
With this, the soft tissues in the shoulder region can become injured and painful, particularly during activities that involve arm elevation above shoulder height.
|Transverse processes of 1st four cervical vertebrae||Medial border of scapula||C3 and 4 and dorsal scapular nerve||Raises medial border of scapula|
A long and slender muscle
Prone to stiffening and chronic pain due to false posture in everyday life. Common causes include carrying heavy shoulder bags, permanent lifting of the shoulders while sitting at a desk and sleeping on one side of the body without proper head support
Can be palpated by placing the client in supine position, stabilizing the ipsilateral scapula, and contralaterally side bend and rotate the head
|Iliac crest, lumbar fascia, spines of lower six thoracic vertebrae, lower three or four ribs, and inferior angle of scapula||Floor of bicipital groove of humerus||Thoracodorsal nerve||Extends, adducts, and medially rotates the arm|
Largest muscle in the upper body
Also known as the "lats"
Are large, flat triangular muscle that connect your arms to your vertebral column
Latissimus dorsi is a climbing muscle
With the arms fixed above the head, it can raise the trunk upwards, together with the help of pectoralis major
It is an important muscle in activities such as rowing and swimming.
It is also active in violent expiration, as it attaches to the ribs. Therefore, during a cough or sneeze, it can be felt pressing forcibly inward, as it acts to compress the thorax and abdomen
|Occipital bone, ligamentum nuchae, spine of 7th cervical vertebra, spines of all thoracic vertebrae||Upper fibers into lateral third of clavicle; middle and lower fibers into acromion and spine of scapula||Spinal part of accessory nerve (motor) and C3 and 4 (Sensory)||Upper fibers elevate the scapula, middle fibers pull scapula medially, lower fibers pull medial border of scapula downward|
A large paired surface muscle
The trigger points of this muscle is along the bands of the trapezius may be developed from exercise, inactivity, or working for prolonged periods with a poor posture (e.g. with your head down).
|Upper eight ribs||Medial border and inferior angle of scapula||Long thoracic nerve||Draws the forward anterior around the thoracic wall; rotates scapula|
A fan-shaped muscle at the lateral wall of the thorax
Also known as the “boxer's muscle,” as it is largely responsible for the protraction of the scapula, which is a movement that occurs when throwing a punch
Serratus anterior pain is known to be common in sports with repetitive motions, such as swimming, tennis, and weightlifting. This pain may also result from Serratus Anterior Myofascial Pain Syndrome or SAMPS
Since this muscle is very thin and covers the side of the ribcage, it can be palpated by placing your hand just below the armpit
|1st costal cartilage||Clavicle||Nerve to subclavius from upper trunk of brachial plexus||Depresses the clavicle and steadies this bone during movements of the shoulder girdle|
Short, triangular muscle of the thoracic wall
Lies underneath the clavicle
|3rd, 4th and 5th ribs||Coracoid process of scapula||Medial pectoral nerve from brachial plexus||Depresses point of shoulder; if the scapula is fixed, it elevates the ribs of the origin|
Lies underneath Pectoralis Major
A thin, triangular muscle, situated at the upper part of the chest
This muscle can be palpated by placing a finger in the axilla and pushing obliquely towards the coracoid process of the scapula
|Clavicle, sternum, and upper six costal cartilages||Lateral lip of bicipital groove of humerus||Medial and Lateral pectoral nerves from brachial plexus||Adducts the arm and rotates it medially; clavicular fibers also flex arm|
The most superficial muscle in the pectoral region
Large and fan shaped
Composed of a sternal head and a clavicular head:
|Clavicular head||– originates from the anterior surface of the medial clavicle|
|Sternocostal head||– originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle.|
is formed in the posterior triangle of the neck by the union of C5-T1
the plexus can be divided into roots, trunks, divisions, branches (3 anterior and 3 posterior divisions) and cords
Cords of the Brachial Plexus
All three cords lie above and lateral to the first part of the axillary artery.
Anterior divisions of the upper and middle trunks form the lateral cord
Lies on the lateral side of the 2nd part of the artery
Anterior division of the lower trunk form the medial cord
Crosses behind the artery to reach the medial side of the 2nd part of the artery
Posterior division of all three trunks form the posterior cord
Lies behind the 2nd part of the artery
Supplies the coracobrachialis muscle, and leaves the axilla by piercing that muscle
Distributes at Coracobrachialis, biceps brachii, brachialis muscles;
Supplies skin along lateral border of forearm when it becomes the lateral cutaneous nerve of forearm
Lateral pectoral nerve
supplies the pectoralis major muscle
Lateral root of median nerve
the direct continuation of the lateral cord of the brachial plexus.
joined by the medial root to form the median nerve trunk
passes downward on the lateral side of the axillary artery.
gives off no branches in the axilla
Medial pectoral nerve
supplies and pierces the pectoralis minor muscle, and supplies the pectoralis major muscle
Medial cutaneous nerve of arm
joined by the intercostobrachial nerve.
It supplies the skin on the medial side of the arm.
Medial cutaneous nerve of forearm
descends in front of the axillary artery
descends in the interval between the axillary artery and vein.
gives off no branches in the axilla.
Median root of median nerve
crosses in front of the third part of the axillary artery to join the lateral root of the median nerve
Upper and lower subscapular nerves
supply the upper and lower parts of the subscapularis muscle.
the lower subscapular nerve supplies the teres muscle
runs downward to supply the latissimus dorsi muscle
It turns backward and passes through the quadrangular space
Having given off a branch to the shoulder joint, it divides into anterior and posterior branches;
wraps around the surgical neck of the humerus, running in the deep deltoid fascia with the posterior circumflex humeral artery
supplies the anterior deltoid muscle
terminates in small cutaneous branches supplying the anterior and anterolateral shoulder
supplies the teres minor and posterior deltoid muscles
pierces the deep fascia
terminates as the superior lateral brachial cutaneous nerve supplying the lateral shoulder
is the largest branch of the brachial plexus
lies behind the axillary artery
Roots of the Brachial Plexus
Long thoracic nerve (C5, 6, and 7)
arises from the roots of the brachial plexus in the neck
enters the axilla by passing down over the lateral border of the 1st rib behind the axillary vessels and brachial plexus
Supplies and descends over the lateral surface of the serratus anterior muscle
Dorsal scapular nerve (C5)
Arises from the plexus root (anterior/ventral ramus) of the C5.
it commonly pierces the middle scalene muscle, and continues deep to levator scapulae and the rhomboids
Trunks of the Brachial Plexus
C7 forms the middle trunk
C8 and T1 form the anterior/lower trunk
C5 and C6 form the superior/upper trunk
the following nerves in this category:
Nerve to subclavius (C5 and 6)
supplies the subclavius muscle
It is important clinically because it may give a contribution (C5) to the phrenic nerve
supplies the supraspinatus and infraspinatus muscles
The combination of the scapula, clavicle, and humerus allows the link of the upper extremity to the
thorax and it is primarily designed for mobility, and for positioning the hands through a wider range of space.
Below are the different types of joints comprising and supporting the interdependent linkages of the shoulder complex.
Permits three degrees of freedom:
Occurs around the anteroposterior (A-P) axis found in between the convex and concave clavicular surface which is formed by the manubrium and the first costal cartilage.
With elevation, the lateral clavicle rotates upward.
With depression, the lateral clavicle rotates downward.
Range permitted by clavicular elevation: up to 48 degrees.
Range permitted by clavicular depression: up to less than 15 degrees on average.
Occurs at the sternoclavicular joint around an approximately vertical axis that lies at the costoclavicular ligament
With protraction, the lateral clavicle moves anteriorly
With retraction, the lateral clavicle moves posteriorly
Range of protraction: about 15 to 20 degrees
Range of a greater retraction: about 30 degrees
Also called as a ‘long axis’.
Occurs between the saddle-shaped surface of the medial clavicle and manubriocostal facet
Unlike the other joints, its posterior rotation is referred to as a backward or upward rotation due to the rotation of the clavicle posteriorly from a neutral position which brings the inferior surface of the clavicle to face anteriorly.
As for the anterior rotation, the clavicle just returns to its neutral position.
Range of anterior rotation: less than 10 degrees because the anterior rotation past neutral is limited.
Range of posterior rotation: approximately at 50 degrees.
Allows 3-degree motions of the scapula:
Positioned on the posterior thorax 2 inches from the midline, between the 2nd through the 7th rib.
Atmospheric pressure is the force that holds the scapula to the thorax.
The stability of this structure is provided by structures that maintain the integrity of acromioclavicular and sternoclavicular joints.
To orient the glenoid fossa for optimal contact with the humeral head of the maneuvering arm.
To add range of motion in elevating the arm.
To provide a stable base for a more controlled motion between humeral head and glenoid fossa
Also called a ‘dynamic stabilizer’ in the human body
Sternoclavicular (SC) joint
A plane synovial joint with three rotatory and translatory degrees of freedom:
Elevation-depression of the clavicle
Protraction-retraction of the clavicle
Rotation of the clavicle
Take Note: movement of the clavicle will produce movement of the scapula
Scapulothoracic (ST) joint
Articulation of the scapula with the thorax
Part of a true closed kinematic chain with the acromioclavicular and sternoclavicular joints
Take Note: Movement of the scapula wouldresult in movement in the sternoclavicular joint.
It is not a true anatomic joint.
Acromioclavicular (AC) joint
Attaches scapula to the clavicle
It is a plane synovial joint that permits 3 degrees of freedom:
Scapula rotation: upward and downward motion of glenoid
Winging: posterior movement of the medial border of the scapula
Tipping: inferior border moves posteriorly while superior border moves anteriorly in a coronal plane